The 2012 London Olympics committee has issued this revised map of the Tube system and event venues. Sadly, it didn't label the stations. Each stop is a letter, and each colored line spells a word that ends with the letters at the terminus. So the letters that would fit on a line ending in EKMY would be S-T-O-R (forming STORE, STORK, STORM, and STORY).
Puzzle: Matt Jones
