Series 4

Harry and Fergus take on a disturbing case-a serial killer targeting random victims and leaving a coin in their mouths. Meanwhile, Harry B. asks a reluctant Harry to travel the world with him. Fergus plans to attend college with Lola.

Harry and Fergus travel to the convent of a silent order of nuns after an old friend asks Harry to investigate a suspicious suicide, believing foul play is afoot. Elsewhere, a familiar face provides a very welcome surprise.

A fun day at the races for Harry and Fergus ends in tragedy when a racehorse throws its jockey from the saddle. Harry B discovers the horse was sabotaged and insists the owner, his father, Duncan, is responsible for the crime.

After two performers go missing from Genevieve Le Coeur's dance school, Orla and Lola persuade Harry to investigate. In search of the truth behind the disappearances, Harry and Fergus dive into the history of the school and its founder.

While attending a crime convention, Harry's look-alike is pushed to her death from a balcony. To stop the killer fleeing Harry and Fergus get security to lock the building down while they investigate. A second murder reveals a chilling connection.

When a heckler dies during a guided tour, the investigation brings Harry and Fergus into the middle of a literature-themed murder plot; in America, FBI agents fail to prevent an assassination by Diyu.