1996 MIT Mystery Hunt Solutions

Shortly after the 2012 MIT Mystery Hunt, the main Hunt site was redone quite nicely, and some additional Hunts (sans solutions) were added into the archives. This of course presents a kind of challenge, and some of the most devoted members of Beginner's Luck took up that challenge. The results of our work are presented below.

Two of us both had the Vintage Books edition, September 1980 printing of Gödel, Escher, Bach, a version that would have been available to solvers and was likely to be the one they used. We don't know if there are other editions with different pagination, but this one worked. All page number references below are to that edition.

Puzzle 1A

No matter what integer is plugged into the formula, taking it modulo 360 gives the answer 29.

Puzzle 1B

The graphic and answer for this puzzle were previously posted on the Hunt web site. The answer is SHOEPRINT.

Puzzle 1C

Starting at the upper end of the string, break the string into trigrams and translate them into amino acids. Then solve the result as a cryptogram. (Some of the letters use the familiar single-letter abbreviations for amino acids, but others are different. Perhaps there was another code in use in the past or perhaps they just made acids stand for their initial letter when possible, without using any established code.) It decodes to:
The beginning and end are junk, but the middle is an instruction referring to the Aria with Diverse Variations that appears beginning on page 391 of GEB. If you just jump to the end of the text on page 405, you will not find the answer. But if you actually read the Aria, you will see that on pages 402-403 the characters discuss the subject of making the reader have to search for the end of a text by putting some red herring content after the actual end. There are several clues, but most notably the missing letters in Tortoise's last speech on page 404 tell you that this speech is the actual end of the Aria, and the knock and the following part is not really part of the story. So the answer is found in that speech, and it is SWEET DREAMS.

Puzzle 2A

Extend the lines through the shapes laid over them, and in each small shape will appear an intersection of lines which forms a letter shape. The letters spell LEAFY LAKE.

Puzzle 2B

The game played here is equivalent to a game called Bogus Nim. You can find references to it online, though at the time of the hunt, solvers would have had to find a book such as the one cited in the flavor text. Summary of the strategy:

Each legal move either adds chips into or removes chips from pile B or pile D. Treat each game as a 2-heap nim game with these heaps, ignoring the others. The game is called bogus because chips can sometimes be added to a pile instead of removed from it. But after the second player makes any such move, the first player can return to an equivalent state by removing those same chips; the first player never needs to do so. Because there is a finite supply of chips to the left of these piles, there is a finite number of moves which add chips available, and so it is effectively just regular nim.

Two-heap nim is easy: You just make the piles the same size. So you win by moving 2 chips out of D, 8 chips out of D, 6 chips out of D, 21 chips out of D, and 5 chips out of B. Concatenate these per the instructions, and write with a comma as suggested by the example, to get the answer 286,215.

Puzzle 2C

This puzzle is on the tape which we do not have.

Puzzle 3A

The 9-letter Boggle words are ADJECTIVE, GENUFLECT, SECRETARY, RIGMAROLE, LUDICROUS, ZESTFULLY, EMPHYSEMA, SYNDICATE, and CIRCUITRY. Per the instructions, find that the consonants that appear exactly three times among the unused letters are D, H, P, R, S, and T, and the vowels which appear exactly 6 times among the unused letters are E and O. The only anagram of these letters is POTSHERD.

Puzzle 3B

This puzzle is on the tape which we do not have.

Puzzle 3C

The two-letter codes are the first two letters of the first 14 distinct names (ignoring initial numbers) of the books in the Protestant Bible: Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua, Judges, Ruth, Samuel, Kings, Chronicles, Ezra, Nehemiah, and Esther. If you stack the cards in this order, with the unlabeled card on the bottom, then a card with letters appears as every 3rd card, and reading through the holes leads to exactly one letter on each card:
It's not particularly obvious from this, but the answer is Unmon, the name of a Zen Master who appears on page 254 of GEB. (The puzzle text says the answer will be a person's name.)

Puzzle 4A

This puzzle is on the tape which we do not have.

Puzzle 4B

The trip-lets, clockwise starting from the top, contain the letter groups TNN, OHT, VIE, SNE, SRC, BEE. Reading one letter from each group in this order, cycling around until all the letters are used, spells "This sentence no verb" which appears on page 495 of GEB. Following the directions below the puzzle on this page leads to the answer floating castle.

Puzzle 4C

The number sequence is 0 9 18 3 12 21 6 15 24 1 10 19 4 13 22 7 16 25 2 11 20 5. This can be interpreted as the results of numbering the cells in a 3x3x3 cube from 0 to 26, then reading out those numbers using a different ordering of the dimensions, and with the last 5 numbers missing. This assigns A through H the values 9, 21, 6, 15, 19, 13, 22, and 25.

Then match the numbers with pieces, rotating them so that the intended numbers are upright. Each number appears on only one piece and exactly one of the numbers appears on each piece. The spaces between the pieces spell ESREVER, which is REVERSE spelled backwards. For the second part of the answer, just plug the numbers into the formula to get 723.

Puzzle 5A

This puzzle is on the tape which we do not have.

Puzzle 5B

Solve the crossword.

Clue 11 down and its answer tell you that you need to fold the puzzle into a tetrahedron. Edge letters that extended beyond the boundaries implied by the dashed lines get cut or folded away. Clue 24 across and its answer tell you that you need to look for answers crossing the edges in the final puzzle. There are three edges that come together to form the tetrahedron (as opposed to simply being folded) and on each one, there is just one space where two squares with the same letter in them meet at the edge. Reading the entries through those spaces yields EDGERTON ROOM NUMBER. There are several places at MIT named Edgerton, but we believe the intended answer was 4-405.

Puzzle 5C

It should be fairly clear that Achilles and the Tortoise are performing a series of transformations on some string of characters. But what string? The Tortoise helpfully suggest you should "start with a complete list of problems", and the text of this puzzle contains several misspelled words: compliment, monsterous, surprize, capitol, congradulations, disfunctional, embarassed, and affect. Concatenating them (without correcting them) gives:


Now remove every other letter, starting with the first:


For every string of all consonants or all vowels of length greater than two, remove all but the first two:


Replace both instances of PIE with CAKE:


Remove all three instances of OS:


Remove the reversed CUE:


Remove the conjunction IF:


Twenty letters remain. Take the last five, reverse them, and move them after the tenth letter:


Change all Rs to Ls and all Ns to Ts:


Remove TAKE:


The FA of "fad" appears in the string; replace it with the D:


Remove CC:


Change the first A to an R, and remove the other A:


And reverse the first two characters, along with the whole second half of the string:


CORKED BOTTLE is the answer.

Puzzle 6A

It doesn't take long to prove that the problem is unsolvable in base 10. χ can't possibly be both small enough to produce a number smaller than 80 in the third multiplication and large enough to produce three-digit numbers with two distinct first digits in the other multiplications. Given that we only have eight distinct letters to work with, base 8 seems worth a try, and sure enough a unique solution falls out:
Now the letters off to the side translate to 467, 103. This needs to be converted back to base 10 to get the correct answer, 311,67.

Puzzle 6B

This puzzle is on the tape which we do not have.

Puzzle 6C

The path is:
A right
R up
I left
E up
T right
T right
G down
I left
E left
T up
T right
E down
T left
A down
R right
M right
I down
T left
A left
R down
Applying the shifts as instructed yields DSITEPJBIVALVEXMBNET. The clear longest word is BIVALVE.

Puzzle 7A

To solve this puzzle, write the alphabet above the pangram:
Use this as a cipher key, decoding J, the number above 1 in the example, once by finding the letter below where J appears in the alphabet, which is P. Do the same for N, which appears above 2, but do it twice, decoding N to B and B to U. Continuing in this way yields PUZZLERS. Doing the same for the second set yields HAUSSMANN, the answer.

Puzzle 7B

  1. We did not go hunting for the illustration which may or may not still be available in Samuel Adams park.
  2. We backsolved this answer first, but upon seeing it was a six-letter answer, so the first word needed to be four letters, we determined the correct illustration is the neuron on page 339, which contains word A, GLIA, which is the anagram of Gila, the name of a monster.
  3. The first acronym after glia in the index is GOD which it specifically says is an acronym. Its last page number, (a), is 722. This is in the Six-Part Ricercar where they are making up alternate titles for GEB, and the second such title is Giraffes, Elephants, Baboons: an Equatorial Grasslands Beauty, so the third initial is B. Replace the A in GLIA with a B to spell GLIB.
  4. The first word of the first title on page 722 is Copper. The only page listed in the index for copper is (b), page 173. The text describes a picture made of dots (forming the Fibonacci sequence) and says a colon after the word "another" is an example of this picture with 2 rows. So the fifth letter before the "picture" is an O, which replaces the I to spell GLOB.
  5. The third numeral on page 173 is 2, and the sixth is 8 (again from the Fibonacci sequence). So (c) is 2+8 = 10 and we go to the 10th listing in the index, acoustics, on pages 7 and 81, so (d) is 81. The first letter on page 81 is an E. Now e have GLOBE.
  6. "Would" appears about halfway down page 81 after the word "it", so alpha is a T. The last T entry in the index is "typos" on page (e) 404. In the Tortoise's last speech here, which is (per comments earlier in this dialogue) the real end of the dialogue, three letters are omitted from words, spelling END, to signal that this is the real end. The D is missing from "Golbach", so we remove the G.
  7. The first name in the the list on page 404 (beta) is De Morgan. The 30th entry before De Morgan in the index is "cows" and its third page number, (f), is 351. The first two-digti number on page 351 is 18. The 18th letter of the alphabet is R. We can replace either the L to get ROBE or the B to get LORE.
  8. The last letter in the last paragraph on page 351 is Y. The first index entry starting with Y is yes-answers. The first page referenced there is (g) 461. The first letter on page 461 is B. Presumably we aren't meant to go back to LOBE or replace a B with a B, so the most reasonable result is that word F is LORE and word G is BORE.
  9. If the Tortoise counts as a person, then the fourth person mentioned on page 461 is Augustus, King of Saxony. His index entry is on the opposite side of the page from the index entry for "and", and three below this is (gamma) "anomalies". The forth page for that is (h) 435. A bit below the middle of the page we find "A king without a subject would be -- an anomaly, of course." The subject of the sentence is "king" and the letter preceding it is A, so we replace the O with an A to get BARE.
  10. Thie historical figure discussed on page 435 is Willard Van Orman Quine. Reverse the letters in his surname to get ENIUQ which is listed as ENIUQ (procedure) in the index.The 41st following index entry (delta) is fermatas, whose first page is 275. A fermata is a pause (and is unrelated to Pierre de Fermat, who is also mentioned on page 275). The last pause is in Achilles' penultimate speech, "Pauses for a moment to sip his tea, then resumes." So the first letter is P. The word immediately above it is "provoked" and its sixth letter, (epsilon) is K. Replace the R with a K to get BAKE.
  11. The seventh index entry starting with K, (phi), is kitchen sink, and its only page (i) is 315. Kitchen sink appears about 1/3 the way down the page and the next proper noun is the name of the next character to speak, Anteater. Its last letter is R, so we get BAKER.
  12. The person discussed on pahe 315 (not the noun used in the last step) is Aunt Hillary, and the index entry mirroring hers on the opposite page is "chunking". The preceding index entry (lambda) is "chunked versions of this book" and the first location listed is jacket. The phrase after the colon on the jacket is "An Eternal Golden Braid". The most frequent consonant in this phrase is N, which gives us BANKER.
  13. The last page listed for chunked versions of this book is (j) 777. Page j-10, or 767, is in the index, and (mu), the last phrase in quotes on this page, is "last step" and its last page (k) is 468. "Last step" occurs near the end of the first paragraph, and the letter immediately following is the N in "necessary". Replace the K with and N to get BANNER, the final answer.

Puzzle 7C

The columns, decrypted:
The properly assembled inventions, and their inventors:
Enter these names into the grid as shown:
Mozart's Fortieth is the answer.

Puzzle 8A

The pattern you have to figure out is that each group of 3 of more letters which contain a stroke running in the same direction (vertical, horizontal, or either of two diagonals) that the letters run in is circled.
The highlighted letters above are the ones not in any such group. They spell CONSTRUCTION WORKERS.

Puzzle 8B

A little experimentation will lead to multiple solutions ending on white's 8th move, so a shorter solution is needed. That solution is:
The sums of the from and to spaces, respectively, are 131 and 112.

Puzzle 8C

This is a phonetic crossword puzzle. You have to enter one phoneme in each square.
The answer is spelled phonetically along the bolded diagonal: BLUE SUEDE SHOES.

Puzzle 9A

We didn't solve this puzzle. But we backsolved the answer CLOTHESPIN which has to belong to either this puzzle or 9B. Alex Fink pointed out after this was first posted that this answer should go to 9A since it causes the threads of puzzles to be "braided" through the 12 rounds, with a repeating ABCCBA pattern.

Puzzle 9B

This puzzle is based on the string which we don't have. But I've been told that the comment in the flavor text about drinks was a clue that you needed to wrap the string around a soda can to line up the markings on it properly to read the answer.

Puzzle 9C

Postal bar codes encode 12 digits using a 2-of-5 code: Each digit is encoded by five bars, two of which are tall. The first and last bars are always tall and are not part of any digit. The first nine digits encode the 9-digit ZIP+4. The next two digits provide the last two digits of the street address. The final digit is a checksum such that the sum of all 12 digits is a multiple of 10.

Each of the zip codes leads to a university, but for some of them, the checksum is wrong. Those wrong checksums are struck out below:

Skipping the invalid barcodes, read the first letter of the first school, the second letter of the second school, etc. as instructed, and shift each letter back one position in the alphabet (which is done on page 404 of GEB as an imitation of Cantor's diagonal proof that the real numbers are uncountable) to get Hartley Rogers.

For the second part of the answer, Oberlin, Haverford, and Kalamazoo were all founded in 1833. The youngest school is Hawaii Pacific which was founded in 1965, so was 31 years old at the time of the Hunt. The oldest school was Columbia, founded in 1754, 242 years old at the time of the Hunt. Dartmouth and Brown were also founded before 1800. Perform the calculations specified to get 476.

Puzzle 10A

This web-based puzzle and its solution are already on the web site, and the answer is Somewhere Over the Rainbow.

Puzzle 10B

The solution to the domino puzzle is:
1 0 0-6 5 6-4 5
| |     |     |
1 2 2-1 3 3-4 2

3 0 3-1 4-5 6-6
| |
3 1 6 0-0 2-4 6
    |         |
2-2 5 5 6 2 4 1
      | | | |
4 5-0 1 3 3 0 2
|             |
4 3-0 5-5 4-1 6
The letters corresponding to horizontal dominoes spell Rind on the Wall.

Puzzle 10C

The puzzle is based on the Qwerty typewriter keyboard. Each letter is either the correct one or one of the two letters adjacent to it in the same row of the keyboard. All spaces and punctuation are correct. It decodes to the following paragraph, a more detailed version of the anecdote from page 565 of GEB; this version is from The Man Who Knew Infinity, a biography of Ramanujan published in 1991.
"I was talking the other day," said William Rogers to the other villagers gathered around the inn fire, "to a gentleman about the place called Louvain, what the Germans have burnt down. He said he knowed it well...used to visit a Belgian friend there. He said the house of his friend was in a long street, numbered on this side one, two, three, and so on, and that all the numbers on one side of him added up exactly the same as all the numbers on the other side of him. Funny thing that! He said he knew there was more than fifty houses on that side of the street, but not so many as five hundred. I made mention of the matter to our person, and he took a pencil and worked out the number of the house where the Belgian lived. I don't know how he done it." Perhaps the reader may like to discover the number of that house.
The answer to this puzzle is simply the answer to the math problem (the one which fits between the limits of 50 and 500), which is 204.

Puzzle 11A

The solution to the cryptic crossword is:
The songs are from the 1890s. The letters in the shaded squares spell the answer Try to Remember. Clue answers:

Across: 1. song. 10. EYESIGHT - EIGHT. 11. RE(CAFE)D rev. 12. song. 13. dbl. def. 14. EDITOR IS anag. 16. song. 19. hidden: abroAD A Romantic. 20. RUIN MY anag. 22. HOY rev. + O. 26. BEG ALMS anag. 28. song. 29. hidden: tEXAn. 30. EASTER anag. 31. LOVER (L moved to end) + IE. 32. song. Down: 1. TRI(B)AL 2. DADDY -DY + ED? 3. HAMFATTER anag. 4. LIAR rev. 5. AS INCHES anag. 6. O + RIB + I. 7. M OR N (m and n are both abbreviations for noon, m from the Latin meridies). 8. song. 9. A + MEN. 12. song. 15. LOOT rev. 17. D + ANGORA - ORA. 18. song. 21. I'M rev. + A + OW. 23. HE(X)ED. 24. hidden: hasTY ROmeo. 25. hidden: bunGLE Every. 27. A RAM rev. 28. M + AM.

Puzzle 11B

After selecting the 9 spaces indicated, there are only 2^16 ways for mines to lie ignoring all the other clues. These can be easily programmatically examined (even by 1996 computing standards) to calculate the clue numbers each one would yield, discarding any sets where the clue numbers violate the given clues (any 0s, more than 2 of a number, or fewer than 3 solutions). Out of the remaining solutions, the clue numbers 121463342 are found to have two or more solutions with each of 9 mines, 10 mines, and 11 mines, and thus none of these can be the number of mines. Clues 122464353 lead to multiple solutions with 12 mines and one with 13, and no other case (save for this case's rotations and reflections) works with any number of mines less than 9 or more than 12. This turns out to be the correct orientation to satisfy the B1 not a mine clue, yielding the board:
1 2@2
@ @ @
After performing the indicated calculation and writing the result in base 36, the answer is 757MSSRS.

Puzzle 11C

1 is ^, 2 is <, 3 is /, 4 is \, 5 is >, 6 is V. This yields the path:

And the letters corresponding to the indicated steps translate to ECHECS, the French name for chess.

Puzzle 12A

The number sequence consists of the dates of Easter from 1996 to 2036, written with the month and day number concatenated. The missing numbers are 325,413.

Puzzle 12B

It's unclear at first what form should answers should take, especially people's names. It's a great help to notice that there are twenty-six questions, which, along with the presence of easily-gettable, unambiguous answers starting with Q and X, should make solvers suspect there'll be one answer starting with each letter of the alphabet.
  2. RODGERS [to create "Oklahoma!" and "Carousel," respectively]
  3. LAREDO ["The Streets of Laredo" borrows its melody.]
  4. BEETHOVEN [Eroica]
  6. ?
  7. WEILL [The Three-Penny Opera]
  8. ?
  11. JEFFERSON AIRPLANE ["White Rabbit"]
  12. ?
  14. NIPPER
  15. ?
  20. ?
  23. ?
  24. ATHENS, GREECE [backsolved]
A decade and a half has made some of the questions more difficult to research, but it's clear from what we have that the answer is THEME FROM DEEP SPACE NINE.

Puzzle 12C

With a little work it is possible to determine that the previous Life generation to the one shown was:
Forming the answer DINING.

The Impossible Tribar

The last part of the packet consists of 14 pages containing three meta-puzzles. Each of the descriptions of these puzzles clearly states it takes 13 answers as input, but we have only 36 apparent puzzles. However, each of these 14 pages has a letter string at the bottom which is unrelated to that meta.

These strings should all be considered together as an additional puzzle. The similarity of these strings across the different metas should clue solvers in to their relevance. Letter frequencies and some similarities in some of the strings (especially near the beginning and end of string 7, and between the last two strings) can help to determine the encoding used here.

Within each string, starting with the first letter, read every third letter, wrapping around until all letters are used, and then continue with the next string. With normal punctuation, spacing, and capitalization added, this reads:

Congratulations, you have discovered the impossible tribar.

The smallest room number in the 3rd passageway of one of the trails is one of the clues for one of the other trails.

On this latter trail you should take the 1st serial number, divide it by 49 and take the remainder. Do the same with the 2nd serial number except with 61 instead of 49. Do the same with the 3rd number except with 89, with the 4th number except with 53, with the 5th number except with 91, and with the 6th number except with 64. This will give you 6 numbers that you should convert to letters to spell out a clue for the remaining trail.

On this final trail obtain the clue for the 1st trail mentioned above by using the right hand column when you reach the Boston Edison Company. Take row 3 letter 5, row 1 letter 26, row 2 letter 3, row 4 letter 7, row 5 letter 8, row 7 letter 1, row 6 letter 13, and row 5 letter 2.

The first trail mentioned is clearly the last one in the packet, the Bach meta, based on a partial map of MIT. The answer it provides will be a room number, which works as an answer into the Gödel meta. (This was backsolved to be 6-207.) This is the second trail mentioned, which uses serial numbers from fire equipment around MIT. Based on a backsolve of the Escher meta, the word it gives is SYZYGY. The last trail is from the Escher meta. One of the instructions in that trail specifically sends you to the Boston Edison Company (a piece of equipment with their name on it) where we followed the extraction directions to get ODE TO JOY.

Gödel meta

In each numbered set of three puzzles, one of the answers can be interpreted as a reference to some text within GEB, providing the key mentioned in the last bit of instructions. These answers can be specific text located in the book via the index, a page number (starting at the beginning of the page), a page number and a word found on the page (starting at the word), or a page number and a word number, requiring you to count words on that page to find the starting point (up to 413 words in one case). The key strings count ALL letters and numbers that appear starting at this point, including footers and page numbers before crossing to the next page when necessary. Fortunately, the answers are applied in order to the given strings:
PuzzleAnswerStarting point for keyStart of key text
1A29Beginning of page 29Three-Part Invention Achilles (a Greek warrior
2B286,215Page 286, word 215left the game strategically almost the same
3CUnmonJust after Unmon in the heading on page 254If words are bad and thinking is bad
4Creverse, 723The word reverse on page 723reverse order? A few words were changed
5B4-405Page 4, word 405much, that he resolved to buy them all up.
6A311, 67Page 311, word 67question is staring us all in the face
7AHaussmannThe name Haussmann in the photo credit on page 2Haussmann Introduction: A Musico-Logical Offering
8B131, 112Page 131, word 112end in order to avoid the mental effort of keeping track
9CHartley Rogers, 476The name Hartley Rogers on page 476Hartley Rogers' book, to explain. But the intuitive idea
10C204Start of page 204CHAPTER VIII Typographical Number Theory The Crab Canon
11B757MSSRSThe abbreviation Mssrs. on page 757Mssrs. C. H. O. Trevelyan from Sara Turing
12A325, 413Page 325, word 413of all the neurons, and all the interconnections
Tribar6-207Page 6, word 207carried out as well as possible, and it has
The last one of these was backsolved by partial brute force after reducing the scope of possible answers. We knew from the tribar that the answer needed here was an MIT room number which was the smallest in one of the corridors on the Bach map, which only covers buildings 1 through 8 and 10. We used the start of every word in the first ten pages of GEB (which thankfully include three pages with little text) as a potential key, and decoded the first line of 56 characters for each. A function scored each of these by how English-like it was: ETAOIN SHRDLU scored 2 points each, other letters 1, and digits 0. The best score by this function by a wide margin was the correct decoding.

Decoding the Instructions

All the key texts have been found, and all of the messages have been decoded. These are (with capitalization, punctuation, and spacing added):
  1. This trail consists of ten checkpoints which you must visit in order. Each checkpoint consists of an MIT room plus a piece of fire equipment in or on one of the walls of the corridor just outside the room. The white serial number on the blue number plate associated with the piece of fire equipment at a checkpoint specifies, according to the rules given below, the building number of the next checkpoint on the trail. The rules below also tell you the room numbers of the checkpoints and the order in which the rooms must be visited. By a room number, we mean that the building number is excluded, e.g., the room number of 26-100 is 100. The first building number is 2. When you are done, plug the ten serial numbers into the formula for the final answer.
  2. The 3rd digit of the current serial number equals the twelves digit of the building number of the next checkpoint, when said building number is written in base twelve.
  3. Room 282 should be visited immediately after room 321e.
  4. Between your trips to rooms 365 and 034, not necessarily in that order, you should make trips to three other rooms.
  5. Immediately after visiting room 034, head for room 001. Visit room 562 before room 282 but not necessarily immediately before.
  6. Go to room 551 immediately before going to room 207.
  7. Be sure to visit room 365 immediately before room 044.
  8. The fifth digit of the current serial number plus the building number of the next checkpoint is divisible by three.
  9. Take the difference between the sixth digit of the current serial number and the building number of the next checkpoint. This difference will be divisible by four.
  10. You should go to room 207 exactly five checkpoints after room 023.
  11. After, but not necessarily right after visiting room 001, visit room 321e. Stop by room 044 right before room 023.
  12. Visit room 562 before room 551, but not necessarily immediately before.
  13. Add an E to the front of any building number containing a 5. If the third and fourth digits of the current serial number are 20, then the piece of fire equipment associated with the next checkpoint is a fire extinguisher; otherwise, it is a firehose.

Runaround Reconstruction

Clues 1, 2, 8, 9, and 13, taken together, tell you how to find the building numbers, described concisely as follows: The first building number is 2. If the third digit of the serial number you find near one room is c, the fifth digit is e, and the sixth digit is f, the next checkpoint is in building 12c + (8e+9f)%12, where % is the modulo operator. If the building number contains a 5, add an E in front of it. Additionally, clue 13 tells us to look for a fire extinguisher whenever our previous serial number has 20 as the third and fourth digits, and a fire hose otherwise.

The other clues tell us all the room numbers and the order to visit them. Two of these provide two separate clues which I have labeled a and b in the logic that follows.

Clues 3, 5a, 6, 7, and 11b give us several pairs of rooms that must be visited consecutively and in order: 321e-282, 034-001, 551-207, 365-044, 044-023. The last two pairs obviously combine into a single block of 3.

Clue 10 tells us 207 is exactly five checkpoints after 023, so this gives us the block 365-044-023-?-?-?-551-207.

Clue 4 tells us to visit three other rooms between 365 and 034, not necessarily in that order, which gives us one of the following two groupings: 034-001-?-?-365-044-023-?-?-?-551-207 or 365-044-023-?-034-001-551-207. The first of these is impossible because it is longer than 10 checkpoints.

We have the following additional clues which tell us to visit two rooms in a particular order, but not necessarily consecutively: Clue 5b: 562 before 282. Clue 11a: 001 before 321e. Clue 12: 562 before 551. Clue 11a forces the 321e-282 pair to come at the end of the sequence (immediately after 207, or else the sequence is too long). Then either of the other two clues is sufficient to place the remaining room (just by telling us that that room is 562, but for confirmation, both clues are correct) So the room sequence is 365-044-023-562-034-001-551-207-321e-282.

We attempted to perform this runaround. At 2-365 we found serial number 752512, which sends us to building 26. At 26-044, we found serial number 750996, which sends us to building 6. At 6-023, the closest serial numbers are 730506 and 730641, which would send us to buildings 6 and 5, respectively. The first two of these serial numbers match the first two letters of the backsolved answer SYZYGY which we got from the Escher meta, using the procedure described in the tribar solution. But neither of these serial numbers in building 6 works for the next letter (which should give us a serial number which is 26 modulo 89), so we think they are both wrong. There was a significant remodeling of building 6 which was completed in 2007, and we fear that this has caused the replacement or relocation of the fire equipment originally located near this room.

It may be possible to pick up the trail given that the next room number is 562, and most MIT buildings either do not have a 5th floor or do not have enough rooms on the fifth floor to number up to 562. It may even be possible then, given the third digit of the serial number, the last two digits each limited to 3 or 4 possibilities, that the number is six digits beginning with a 7 (at least, all the ones I have seen are), and that it must be 26 modulo 89, to backsolve the number that was supposed to be here (especially if it is a fire extinguisher and we know the fourth digit as well), or at least limit it to a handful of possibilities.

Escher meta

In each set of three puzzles, one answer is the name of something seen (or possibly seen, anyway) in one of Escher's artworks. We found most of them in numbered figures in GEB. These are:
These answers are applied to transpose the code strings found in this meta, in the given order (i.e. SHOEPRINT for the first code string, LEAFYLAKE for the second, etc.). The resulting strings should be written as columns and then rearrenged so that the result makes sense. We did not find any specific ordering mechanism for this (it was not based on the figure numbers), but there is plenty of information available to solve it. In fact, we solved this with only 10 answers (missing the answers for 7, 9, and the tribar), and were able to determine all three missing answers, by locating the letters needed to complete words near the beginning of the text in the code strings and computing the offsets required to reach them. This leads to the following set of instructions, which are numbered here only for convenience:
  1. Begin at the Escher painting next to 24-608. At no time from now on should you walk up a flight of stairs.
  2. Walk toward the dark green lizard.
  3. Exit to your left.
  4. Find the floor with the A.P.C. Project P.E.P.R. sign.
  5. Go through the forest of carpets.
  6. Exit left.
  7. Find Board #AK220833.
  8. Find the wheelchair elevator close by.
  9. Go past the flying man.
  10. Exit,building by the exit closest to 755733.
  11. Go through the swinging double doors.
  12. Stand underneath the seventh sprinkler.
  13. Walk toward the pair of dragon eyes.
  14. Keep going.
  15. Go up a story when it's time.
  16. Go in the direction of the xylotone.
  17. Keep going.
  18. Turn away from the Marriott.
  19. Immediately after passing the teal arch, go through the door on your right.
  20. Go through the first door on your left.
  21. Pass bulletin boards on your right.
  22. Stand under the exit sign.
  23. Go straight until the third light fixture.
  24. Walk to the Boston Edison Company.
  25. Keep going; at the next choice, choose blue over green.
  26. Soon, you will be tempted to go up a story, but don't. Instead, keep following the white strip.
  27. Enter next building, then open door slowly.
  28. Take the next door on the left after passing by a blackboard.
  29. Keep going.
  30. Go down stairs at the next opportunity.
  31. Make a hairpin turn at Halsey Taylor.
  32. Exit building.
  33. Walk toward the Blue Fearsome Idol.
  34. Enter double door immediately behind the Blue Fearsome Idol.
  35. Go up two stories at the next chance you get.
  36. Walk toward the coke machine.
  37. Pass underneath chilled water supply pipes.
  38. Pass through double doors.
  39. Go by XYZ.
  40. Go through double doors.
  41. Stop at the mail drop.
  42. Walk to the drinking fountain.
  43. Go through green door.
  44. Enter the next corridor on your left.
  45. Go through the sixth door on the left.
  46. Take an immediate right, then an immediate left.
  47. Look for a wolf, a castle with gates, and a dove on your left.
  48. Take the next available left.
  49. Walk toward BOSTON.
  50. Walk toward Boston.
  51. Stop before the closed double doors.
  52. The inscription just on your right gives the teleport spot.
  53. Teleport to: 75 26 50 40 14 72 105 18 102 11 67 107 106 37 22 45 49.
  54. Enter where it says Do Not Enter.
  55. Go through the first available double doors on your left.
  56. Go up three stories
  57. Find signs with black on white arrows.
  58. Follow the direction pointed to by more arrows.
  59. At the next intersection, turn toward the direction of the light switch.
  60. Keep going.
  61. At the next intersection, pick the locks.
  62. Keep picking locks until you run out of locks.
  63. Don't enter the hallway with David waiting at the end.
  64. At the next fork, take the blue door.
  65. After passing the green door, go through the next door.
  66. Go to the nearest elevator.
  67. Walk toward the other elevator.
  68. Find the regular pentagon. Go to it.
  69. Go through the door located on the left of the pentagon.
  70. 26 16 46 9 29 36 18 2 18 38 12 47 32 14 39 13 10 29 11 5 4

Some comments:

We followed this runaround up to the Boston Edison Company, where we performed the letter extraction described in the Tribar, and then to step 32, which puts you into the alley between buildings 35 and 37.

Bach meta

Five of the puzzles for this meta are found on a tape which is not yet in the archives, and we have solved none of those. We also lack the answer to 9B, which depends on the string we do not have. The answers we do have are given below; we know from the meta that each of them is the title of a musical work.
1CSweet Dreams (the puzzle confirms this is the song by Air Supply)
2C[on tape]
3B[on tape]
4AAdeste Fideles [backsolved]
5A[on tape]
6B[on tape]
7CMozart's Fortieth
8CBlue Suede Shoes
9B[on string]
10ASomewhere Over the Rainbow
11ATry to Remember
12BTheme from Deep Space Nine
TribarOde to Joy

Backsolving provided one of the others, Music of the Night, but we don't know which puzzle it goes with.

This meta was unsolvable, even during the Hunt in which it was run. There were attempted corrections given (which are not in the archives), but even then it had to be scrapped. We have noticed, for instance, (even after considering that notes connected by a tie are treated musically as a single note) that staff 13 contains 15 notes, while it should only contain 14.

Even if we did manage to find all the correct songs, and the correct music for them, and resolve all the other errors, in order to find the runaround path, the solution then depends on the letters on the window panes in the doors along the path it describes. While many of these door inscriptions have been around for ages, they do sometimes change, and building 6 in particular was heavily remodeled several years ago. Even one changed door inscription could lead to wrong letters in the answer we get from this meta -- which the puzzle tells us will not be intelligible text, so we would never know.

Ultimately the answer had to be given to teams. This answer, per the instructions, is a string of gibberish letters that presumably the answers to the other two metas tell us how to decode. Mark Gottlieb describes the event in his 1998 thesis, Secrets of the MIT Mystery Hunt: An Exploration of the Theory Underlying the Construction of a Multi-Puzzle Contest:

The error in the 1996 Hunt was major and it was handled extremely well by the Puzzlemasters. This Hunt had three separate endgame puzzles; only one was broken. The team in the lead (Chaos; again, this was my team) had made great headway into the flawed puzzle; no other team was able to begin solving it. Chaos held approximately a five-hour lead over the second-place team based solely on the progress made on this endgame. This puzzle hadn't been test solved, so Chaos was actually the first group of people to attempt it. The puzzle was riddled with errors and subjective musical interpretations, so Chaos had worked closely with the PM's on this puzzle for a number of hours. (This collaboration allowed the PM's to correct their puzzle for other solvers and it allowed Chaos to make progress on it.) After a while, it became clear to both parties that this puzzle could not be successfully solved; meanwhile, the rest of the teams were complaining that they couldn't even begin to try. This endgame, the culmination of one-third of the contest, would have to be scrapped . . . the PM's released the answer to Chaos, waited thirty minutes to respect Chaos's lead, then gave everyone else the answer. Chaos went on to win the Mystery Hunt by that thirty-minute lead.

Despite this, tacotortoise on Livejournal (not to be confused with the Tortoise in this hunt) attempted to solve it anyway. He figured out Music of the Night and Adeste Fideles as two of the missing answers by examining the available notes. In the following images, each tune is marked with these abbreviations under each note:

Any note with a question mark is uncertain. Comments about these appear after each page. Some general comments from tacotortoise: "They seem to be inconsistent about whether accidentals carry through the line. If there is an accidental on a note, I would trust it, but be wary of other notes. Some of the durations in DS9 may be inaccurate; it has some irregular rhythms that are hard to transcribe. BSS and SD both get a little shaky around the third page; I don't trust their transcriptions (or lead sheets) at all. For BSS, they seem to be basing the melody off of Elvis Presley's version, but transposed from the key of Bb to the key of D. Or, again, their sheet music may have been a bit off."

In line 1, DS9 should be a 16th note G. In line 3, SotR should be a quarter note A above the staff. In line 9, AF should be a quarter note B natural, and DS9 should be a 16th note G.

Additionally, the tribar solution gives us a starting point, the 3rd segment of the path. With this we can fill in segments 2-5, but there are multiple paths beyond that with the remaining available notes.