( Yannick Bisson ): Leads the investigation into the clown killings.

Set in October 1909, the episode begins with a young woman, Irene Robbins, being stabbed to death by a clown while spending an evening with her boyfriend, Perry Balfour. Balfour survives, but his account of the attack conflicts with the autopsy findings of Coroner Violet Hart. As Murdoch delves into the mystery, he discovers that a similar "killer clown" had terrorized students at Jarvis Collegiate the previous Halloween, suggesting a vengeful motive.

: While Murdoch handles the grim investigation, the rest of the team engages in seasonal festivities. Detective Watts participates in a pumpkin-carving contest at Station House No. 4, proving he is a much better detective than an artist.