Pennsylvania miner Harry Belafonte emerges from a cave-in to discover the coal field, and indeed all of Pennsylvania, deserted. By the time he reaches the eerie empty streets of New York City (these scenes were filmed at daybreak, just before the Friday "rush hour"). Belafonte has pieced together the situation: a mysterious radioactive cloud has killed off everyone else on Earth. After an hour or so of singing to himself and conversing with department store mannequins, Belafonte discovers that another human being, beautiful Inger Stevens, has survived the cataclysm. Tentatively overcoming inbred racial considerations, Belafonte and Stevens make the best of their situation (he even throws her a birthday party). But when Survivor No. 3 Mel Ferrer shows up, all the old hostilities and suspicions that have plagued Mankind for centuries are brought to the fore.