Training Exercise

For this puzzle, we ask that you imagine a theoretical near-future world in which the following things are true:

  • The MBTA's Silver Line, commuter rail, and buses no longer exist. (Devoured by locusts. Tragic. Luckily nobody was hurt.)
  • Branching of lines in the MBTA is a thing of the past. The only portion of the Red Line that still exists is those stops which one would encounter by riding from Braintree directly to Alewife, and the only portion of the Green Line that still exists is those stops which would encounter by riding from Riverside directly to Lechmere. (Quicksand accident. Couldn't be helped. Good thing everyone got out okay.)
  • Teleportation has been perfected, and the people of Boston and Washington, D.C. could think of nothing better to do with it than to whimsically link up identically-colored subway lines in endless loops. For every terminus in Boston and in D.C. (with the exception of the termini of D.C.'s Yellow Line), a two-way teleporter exists a short distance past it such that a train that reaches the end of the line will emerge from a teleporter into a terminus of the line of the same color in the other city; in this way, a traveler could in theory stay on one line forever, looping between Boston and D.C. The teleporters are paired such that entering a teleporter near the alphabetically earlier of a line's two termini will send your train to the teleporter near the alphabetically earlier of the other line's two termini. D.C.'s Yellow Line is a special case - it has no Boston counterpart, and so its teleporters lead to one another.

When following the following instructions, use the maps here and here with the above modifications as your sole sources.

A station's only name for the purposes of this puzzle is the exact name assigned to it by these maps. Disregard any punctuation or spacing when determining a station name's alphabetical position or length. Do not consider marked transfer stations in Boston to be transfer stations unless they serve two lines which still exist. Changing lines at a station in D.C. which is served by two lines but is not marked as a transfer station is allowed, but such stations should not be considered "transfer stations" and such an act should not be considered to be "transferring" for the purposes of any instruction that use these terms. Do not consider it possible to transfer onto the Green Line from Downtown Crossing.


  1. Begin, of course, at Kendall/MIT. Ride towards Alewife. Pass two transfer stations.
  2. Transfer to the Blue Line at the first opportunity. Note the first letter of this transfer station. When your train leaves the station, the first station you pass through should have exactly one initial letter in common with the station you just left.
  3. At the first station where you can transfer to another line, remain on the Blue Line. At the next station where you can transfer, change to another line, traveling in a direction such that the next station would offer an opportunity to transfer to the Green Line. Note the first letter which appears immediately before a consonant in the color of the line you are now riding on.
  4. At the next station where you have the opportunity to transfer, observe the colors of the lines that station serves, including the one on which you're currently riding. Develop a sudden strong distaste for them all. Take the next opportunity you have to transfer to any line of a color different from the colors of all of these lines. Note the sixth letter in the longest word in the name of the station where this transfer occurs. After transferring, travel toward the adjacent station that is the later of two alphabetically. Get over your color distaste just as suddenly as you developed it - you have a puzzle to complete.
  5. At the next station where trains on exactly three lines, one of which is the Blue Line, can be boarded, board the Blue Line. Travel on the Blue Line in the direction of the adjacent station with the shortest name. Note the first letter that is doubled at the first station whose name contains one or more pairs of doubled letters.
  6. Whoops! The Blue Line wasn't what you wanted. Get off and board the Blue Line train heading in the opposite direction. When you get back to the three-line station where you most recently changed lines, switch to the line you neither boarded nor left in the previous step. On this new line, look ahead in both directions to find the nearest station that ends with a shape (or an abbreviation thereof). Of these two stations, travel in the direction of the station whose shape has fewer corners. Take that, Hounds of Tindalos!
  7. Continue traveling until you teleport. After teleporting, transfer at the third station where a transfer to a different line is available if and only if that station's name ends with a letter in the first half of the alphabet. If you transfer, travel in the direction of the adjacent station whose name is alphabetically earliest. Keep traveling on this line until you teleport, noting the first letter of the name of the last station you travel through before you teleport.
  8. At the first station where you can transfer, make one of the following transfers, if it is possible to do so. If none of these transfers is possible, remain on your current train and do not transfer.
    • transfer to the red line if you were riding the green line
    • transfer to the green line if you were riding the red line
    • transfer to the blue line if you were just riding the orange line
    • transfer to the orange line if you were just riding the blue line
    If you do transfer, travel in the direction of the adjacent station whose name is alphabetically earliest.
  9. Note the first letter of the first station you encounter whose name is exactly eight letters long. Continue traveling to the ninth station beyond this eight-letter station.
  10. You suddenly feel nostalgic. Note the fifth letter of the name of the first station you reached after your most recent teleport.
  11. Thinking about the past has made you uncomfortable with your immediate future. If it is possible to transfer to another line at your current station, then do so, transferring to the train that would take you to the adjacent station which is alphabetically first; otherwise, disembark and get on a train going the other direction. Travel until you reach a station which has an eight letter word as all or part of its name. (If when transferring, you have the option of transfering to one of multiple lines, transfer to the line which has the closest station which includes an eight letter word in its name.) Note the first letter of this station's name.
  12. Continue travelling on your current line, teleporting once, then stop at the 15th station after the teleport. Note the seventh letter of the station's name.
  13. You look ahead. You like where you're headed, but not the way you're heading there. If it is possible to switch to a different line that will take you directly from your current station to the next station on your current line, then do so.
  14. Ride five stops. Note the last letter of your current station's name.
  15. That feeling of discomfort with the way you're going has returned. If it is possible at your current station to change to a different line, do so, traveling in the direction of the alphabetically last of all adjacent stations on the other line or lines. If it is not possible to transfer to a different line, board the train on your current line which is heading in the opposite direction from which you arrived at this station.
  16. Ride five stops. Note the first vowel of your current station's name.
  17. Randomly decide that orange is now your favorite color. Switch to the Orange Line at this station if it is possible to do so; otherwise, stay on your current train. If you have switched to the Orange Line, travel in the direction of the alphabetically latest station.
  18. Ride two stops.
  19. Randomly decide that green is now your favorite color. If it is possible to switch to the Green Line from this station, do so, noting the first letter of this station as you do; otherwise, stay on the line you are currently on, noting the sixth letter of your current station. If you switch to the Green Line, travel in the direction of the adjacent station with the longest name.
  20. Travel on your current line until you teleport.
  21. Spell out either B-O-S-T-O-N (if you're on the MBTA) or D-C (if you're on the Metro), traveling one stop per letter, and stop when you reach the last letter. Take the third letter of your current station's name.
  22. Hey, that was fun! Let's do it again: spell out either B-O-S-T-O-N (if you're on the MBTA) or D-C (if you're on the Metro), traveling one stop per letter, and stop when you reach the last letter.
  23. Stop at the next station that you can transfer at. If you haven't teleported yet this step, take the 11th letter of the station's name.
  24. Randomly decide that red is your favorite color. If you can't currently transfer to the Red Line, ride until you reach a station where you can. Transfer to the Red Line in the direction of the adjacent Red Line station that's alphabetically earliest.
  25. Wait... maybe you're forgetting something. If you didn't take a letter during Step 23, ride four stops and take the last letter of your current station.
  26. You suddenly feel more sensitive to the needs of others. Travel until you reach a Metro station which offers parking. If it is possible to transfer at this station, transfer to a different line, choosing the train and direction with the adjacent stop with the longest name. Travel until you reach a wheelchair-accessible MBTA station. Take the third letter of your current station.
  27. Randomly decide that purple is now your favorite color. This has no bearing on the remainder of the puzzle, but it's fun.
  28. You can sense you're almost to the end now, and you decide to hurry things. Travel until you reach a station whose name contains an abbreviation.
  29. Time for some more fun with spelling! Your current station is the Magic Station. Disembark and get on a train on the same line going in the opposite direction. Once you've left the Magic Station, spell its name, one letter per station, until you get to a station whose first letter matches the letter you've reached in the Magic Station's name. Note this letter, unless you spell out the entire name of the Magic Station without encountering any such match, in which case note the letter Q.
  30. Become completely sick of riding around both of these areas and disembark in a huff, barely even stopping to notice what your collected letters spell.