Machine Gun McCain

Charlie Adamo pressures Stilberman to sell him a 20% stake in the Royal Casino-Hotel. When Stilberman refuses, Adamo arranges for convicted bank robber Hank McCain to be released from prison via his son, Jack. Jack conceals Adamo's involvement while presenting a plan to rob the casino.

Hank McCain starts casing the Royal Casino-Hotel as part of the planned heist. Along the way, he meets a young woman named Irene, whom he pursues and ultimately marries. This bond ties Irene to the growing scheme and to McCain’s resolve to go through with the robbery.

Don Francesco, the Mafia boss, demands Adamo cease any stake-buying attempt. He is unaware that the Royal is Mafia-owned, and he orders the heist called off. Adamo is pressed to abandon the plot, but the plan lingers.

McCain ignores his son Jack's attempts to reach him and continues with the plan. He meets Jack in a remote warehouse, where Jack reveals that two of his cohorts working for Adamo intend to kill them. McCain disarms the double-cross and kills the two cohorts, while Jack dies in the crossfire.

McCain executes the execution of the plan: placing time bombs throughout the casino and detonating a second explosion outside town to draw authorities away. He then disguises himself as a firefighter and enters the evacuated building to access the safe. The heist proceeds smoothly, but its true masterminds remain at large.

Don Francesco learns of Adamo's involvement through his wife and begins to punish the betrayer. He tortures McCain and Irene's identities out of Adamo, and then has Adamo killed. The mastermind behind the plan is exposed and removed.

With their identities exposed, the Mafia distributes photographs of McCain and Irene across their informant network. The couple have nowhere safe to hide and are forced to run. Their pursuit continues as Francesco's grip tightens.

McCain seeks help from his old partner Rosemary Scott, who arranges safe passage out of the country. Rosemary is soon discovered by Francesco's men, captured, and, faced with torture, kills herself to avoid disclosure. Her sacrifice buys McCain and Irene some time but the danger remains.

An informant spots Irene, leading to her capture by Francesco's men. She is taken to McCain's awaiting boat, where she is killed before they can escape. The loss devastates McCain and fuels his remaining resolve.

Enraged by Irene's death, McCain fires at his attackers but is killed in the ensuing confrontation. Francesco's men dispose of the bodies, ending the would-be crime and sealing the grim fate of McCain and Irene.