The Crimson Feather is the eighth episode of the fifth season of Father Brown.
Mrs. McCarthy's goddaughter Joselyn visits and then disappears. A red feather leads Father Brown to a private gentlemen's club, The Crimson Feather. With Bunty's help, Father Brown discovers Joselyn is at the club, where she has been working for months. When one of the other girls, Verity, is murdered at the club wearing Joselyn's costume, both Bunty (as Pepper Seymore, a burlesque dancer) and Mrs. McCarthy (as a cleaner) take undercover jobs at the club looking for clues. Father Brown discovers Verity's pregnancy, jealousy, unrequited love, and blackmail, along with special services being offered within the club.
Tropes:
- Clothing-Concealed Injury: The final piece of evidence Father Brown uses to identify the killer is that one of the suspects has not removed their gloves since the body was discovered. When the gloves are removed, there is a deep cut on the murderer's palm from the shard of broken mirror they used to stab the victim.
- Dirty Harriet: Bunty goes undercover as a burlesque dancer.
- Janitor Impersonation Infiltration: Mrs. McCarthy takes an undercover job as a cleaner at the club to allow her to look for clues.
- Revealing Injury: The final piece of evidence Father Brown uses to identify the killer is that one of the suspects has not removed their gloves since the body was discovered. When the gloves are removed, there is a deep cut on the murderer's palm from the shard of broken mirror they used to stab the victim.
