The Two Tickets Puzzle

A bloody murder on a train yields impossible questions for a police superintendent in this Golden Age classic—"An excellent straight detective story" (Dashiell Hammett, New York Post).

When the 10:35 local train from Horston arrives at Kempsford Junction, the porter is startled to find a body stowed beneath a seat in one of the first-class compartments. The victim is wealthy businessman Oswald F. Preston, shot five times in the head with bullets of different calibers.

As police superintendent...