It is the Christmas Holidays and reformed thief, Boston Blackie goes to Castle Theater to pick up players who will perform for prisoners that are still in prison. He takes a girl with him who has a brother already in prison. She has visited the prison twice in the month, so is not suppose to visit again. However when the group is completed the girl is included as well as Inspector Farrady. One of the clowns in the show is kidnapped and replaced by a con who wants to get even with two ex-partners. Boston Blackie figures out that a con has replaced one of his clowns but is unable to stop him. Blackie's clothes are stolen and a murder is committed. Of course, the Inspector immediately suspects Blackie of being involved. Now it is Blackie's job to find the killer, exonerate himself and help the girl free her brother.

• Mystery