The Director invites nine-year-old Tommy Whitaker to be a character in a book set in 1957. The trouble begins in the Regal movie theatre, where after the Saturday matinee. Elwood Wambo, the strange caretaker of the movie theatre, hires Tommy and his 1957 best friend, Mouse, to stay behind on future Saturdays to clean the theatre when the movie is over.

The boys later learn that Wambo and his partner Jeremy are part of a gang of thieves. When their friend Smitty’s bike is stolen and when Smitty himself mysteriously disappears, Tommy and his two friends Mouse and Royal vow to solve the mysteries of their missing friend, his missing bike…and a murder.