The Man in Lower Ten, lawyer Ron Hofer travels home by train after taking a deposition pertaining to a fraud case. When Hofer goes to his berth (lower ten) on the Pullman sleeping car, he finds a drunk sleeping there and at the recommendation of the porter, sleeps in unoccupied lower nine instead. When Hofer awakens the next morning, he finds the vital documents in his fraud case stolen and the man in lower ten murdered. Hofer assumes that the murderer intended to kill him, since he was supposed to be in lower ten, and that the murder has something to do with the fraud case. However, because of circumstantial evidence, the police accuse Hofer of the murder. He attempts to prove his innocence and to discover who the man in lower ten was and if he (the victim) was connected to any of the other passengers on the train. The time is the 1950s. The place, a Zepher Pullman train.