When a young Harry Houdini visits Toronto with his stage act, he soon finds himself under police scrutiny when the bank next door to the theater in which he is performing is robbed. A bank guard, Joe Decker, was killed during the robbery. Dr. Ogden and several police officers, including Murdoch and Insp. Brackenreid, were in the audience at the time. For Dr. Ogden the biggest surprise of the evening is that her younger sister Ruby, a reporter and writer, appears on stage as Houdini's assistant. When the autopsy reveals that the dead man's blood has turned black, it would seem that he was poisoned. Brackenreid is convinced that Houdini, who was locked in a safe for over 11 minutes during one of his escape routines, is the culprit but Murdoch is far from convinced. Working with Houdini, Murdoch is able to show how the robbery itself was based on illusion.