America in the 1950s. Donovan, a genius con man, learns that his benefactor, a doctor in the slum where he was born and raised, has been murdered. It happened just as he was leading a movement against the redevelopment of the city. He is sure that the mafia, who are trying to get a bite, are involved. Donovan and his friends vow to take revenge, and after thorough investigation and preparation, they disguise themselves and sneak into a shady casino run by the mafia. Donovan sets a trap according to the scenario he had written, and a young man named Roger, who dreams of becoming a gambler, approaches him. After meeting Rogers sister Sharon, Donovan comes up with a change of plan...