A young doctor accidentally finds a dead body - but the body disappears, and the doctor becomes the target of a determined killer. It's up to his former teacher and friend, Dr. Thorndyke, to uncover the truth.

The killer left his mark - a metal disk in the shape of the letter "Z." Who was the killer, who were his victims, and what was the meaning of that Z?

Nigel Strangeways must find the very unfunny practical joker whose dangerous and deadly pranks threaten to turn the vacation paradise of Wonderland into a deadly trap.

Deputy Chief Constable Bobby Owen tackles a case that begins with a haunted house, the murder of a psychical researcher, and rumors of a fabulous painting that could be worth killing for.