Famous football player Long John is killed and the police believe that John was a heroin addict and that his murder is a punishment for something he did. His mother nevertheless swears that his son hated all kinds of dope and asks Costello to find out the truth whatever the result may be. Costello accepts the appointment and during his investigations notes that Cannon Ball, the best friend of long John, is scared. Also Gonzales and doctor Shuby seem to be involved. When his car blows up Costello gets angry.

A scientist arrives in Miami on a ship coming from Cuba. Detectives Extralarge and Willy have been hired to protect him. The scientist, however, is killed under their eyes without them being able to do anything about it...