Ralph Burton is a miner who is trapped for several days as a result of a cave-in. When he finally manages to dig himself out, he realizes that all of mankind seems to have been destroyed in a nuclear holocaust. He travels to New York City only to find it deserted. Making a life for himself there, he is flabbergasted to eventually find Sarah Crandall, who also managed to survive. Together, they form a close friendship until the arrival of Benson Thacker who has managed to pilot his small boat into the city's harbor. At this point the tensions rise between the three, particularly between Thacker, who is white and Burton, who is black.
Taking the identity of a dead postal inspector found on the trail, a stranger rides into a small western town and finds himself in the middle of a stagecoach robbery perpetrated by a gang of twenty ruthless desperados. Finding out the object of the heist was not a strongbox as it seemed but a solid gold stagecoach, he enlists the aid of a down-and-out old preacher and tracks down the dangerous gang and their unsuspected ally.