Biography of Jackie Robinson, the first black major league baseball player in the 20th century. Traces his career in the negro leagues and the major leagues.

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.

After a rare gem is stolen from an exhibition at a posh hotel, Inspector Farraday decides to recruit former thief Boston Blackie to find the stone. Along with his assistant, "The Runt", Blackie focuses his investigation on the hotel manager, George Daley, and his sister, Eileen. Through disguises and ruses, Blackie and the Runt try to trick their way to discovering the thieves.