23 - Man in Lower Ten by Mary Roberts Rinehart

The task seemed simple enough deliver bank notes to Pittsburgh and obtain a confirmation statement from John Gilmore. However, when McKnight backs out to visit Alison West in Richmond, his law partner, Lawrence Blakeley, is thrust into the mission. Everything seems to be going smoothly until a shocking revelation on the train ride home. Blakeley awakens to find his clothes and the bank notes have vanished from his sleeping carriage. The night takes a darker turn when a murder occurs in a nearby berth and the weapon is found under Blakeleys pillow, making him a prime suspect.