Sherlock Holmes - Season 1 - Episode 24 - The Case of the Night Train Riddle

A young boy and his father are traveling on a train, and after they have a fight, the boy runs out of the compartment and seems to have vanished into thin air. Although his governess thinks he has simply run away, Holmes begins to suspect something a bit more serious, and his investigation leads him to a nearby circus.

Directors: Steve Previn, Sheldon Reynolds, Jack Gage
Writers: Harold Jack Bloom, Arthur Conan Doyle, Charles Early
Starring: Ronald Howard, Howard Marion-Crawford, Archie Duncan, Richard Larke