The Hidden Man is the fifth episode of the tenth season of Father Brown.
Flambeau believes he is being framed for thefts and murders across Europe when valuables he stole 25 years earlier are re-stolen and his handkerchief calling card left at the scene. Because the last item he stole, a gold bracelet, is up for sale at a nearby auction house, he asks for Father Brown's help. Having received an anonymous tip about Flambeau's presence, Inspector Sullivan arrives at the auction house just as a security guard is murdered and the bracelet stolen. Flambeau is captured, secretly passing the bracelet to Father Brown, and claims the auctioneer killed the security guard. Sullivan arrests Flambeau, which may provide his ticket back to Scotland Yard, even though Father Brown finds evidence supporting Flambeau's claim. Father Brown investigates the background of the bracelet, its theft 25 years ago and the suicide of a businessman. He is kidnapped by the killer and his accomplice, and Flambeau escapes from Sullivan to find Father Brown and the bracelet, aided by Mrs Devine and Brenda.
Tropes:
- Calling Card: The killer frames Flambeau by leaving Flambeau's trademark white handkerchief with a red 'F' monagram at the scene of the robberies and murders.
- Frame-Up: Flambeau is being framed for thefts and murders across Europe when valuables he stole 25 years earlier are re-stolen and his handkerchief calling card left at the scene.
- GPS Evidence: From the lavender stains on his boots when he returns from his walk, Brenda and Mrs Devine are able to deduce that Father Brown has hissen the stolen bracelet in the the nearby lavender (although not exactly where in the lavender fields).
- Hero Stole My Bike: Flambeau steals Mrs. Devine's beloved car 'Hercules' to escape from the police at the end of the episode. he abandons it in the woods 20 miles away, and Mrs. Devine is delighted when Sergeant Goodfellow returns it to her.
- Improvised Lockpick: Flambeau uses a staple to pick the lock on his handcuffs while he is being transported in the prison van.
- The Killer Was Left-Handed: Father Brown points out to Inspector Sullivan that the wound on the dead security guard's back was inflicted by someone left-handed while Flambeau is right-handed.
- Master of Disguise: The killer adopts several different disguises over the course of the episode, including posing as the auctioneer and Flambeau's lawyer.
- Pistol-Whipping: After getting Inspector Sullivan's revolver away from him during his escape, Flambeau hits Sullivan over the head with it.