After years of pursuit, Assistant D.A. Martin Ferguson has a good case against Murder, Inc. boss Albert Mendoza. Mendoza is in jail and his lieutenant Joseph Rico is going to testify. But Rico falls to his death and Ferguson must work through the night going over everything to build the case anew.

When two Chicago musicians, Joe and Jerry, witness the the St. Valentine's Day massacre, they want to get out of town and get away from the gangster responsible, Spats Colombo. They're desperate to get a gig out of town but the only job they know of is in an all-girl band heading to Florida. They show up at the train station as Josephine and Daphne, the replacement saxophone and bass players. They certainly enjoy being around the girls, especially Sugar Kane Kowalczyk who sings and plays the...