In 1943, with Rome occupied by the Nazis, Monsignor Hugh O'Flaherty (Gregory Peck) does all he can to help Allied POWs, providing them with hiding places and assisting them in their flight from the Germans. Gestapo Chief Colonel Herbert Kappler (Christopher Plummer) grows suspicious of O'Flaherty, but is frustrated by the priest's diplomatic immunity. Finally, he issues an order that O'Flaherty either be captured or shot if he is ever seen outside the walls of the Vatican.

Gregory Peck, Ava Gardner and Fred Astaire star in this apocalyptic sci-fi drama. In 1964, nuclear war has wiped out all life in Earth's northern hemisphere. After discovering San Francisco to be devastated and deserted, US submarine commander Captain Dwight Towers (Peck) and his crew head for Australia where they await the fallout that will inevitably kill them. Meanwhile, Australian scientist Julian Osborn (Astaire) achieves his life's ambition of winning an auto race and Towers finds romance with good-time girl Moira Davidson (Gardner), who is determined to take one last chance at love.