Tycoon Paul Radin goes to the basement of his office building and checks on two electricians who are installing a projection system designed to simulate a nuclear explosion. The lead electrician wonders at the elaborate lengths Radin has gone to, and the millionnaire notes that while the shelter is authentic, the entire thing is a prank on three of his friends. The electrician notes that they must be very special friends for Radin to spend so muchmoney, and Radin notes they are very special indeed.
Later, three people arrive, two men and a women. Radin greets them and thanks them for coming. Colonel Hawthorne and schoolteacher Mrs. Langsford eventually recognize him. Colonel Hawthorne had Radin court martialed for disobeying a direct order. Langford remembers Radin as a student who she flunked out of her class in high school. They note that Radin summoned them there by claiming it was a matter of life or death and want to know what he wants. Radin explains that he plans to get revenge on them for how they each humiliated and scorned him. Mrs. Langsford thinks he's pathetic despite his wealth, having nursed grudges for so many years. When he notes she could have shown some compassion, she says that while she's shown compassion to many, Radin was a devious child who tried to frame another student when he was caught cheating.
The third person, Reverend Hughes, finally remembers Radin and notes how he drove a girl to suicide and he then condemned him. Radin angrily tells them all to go to the Devil, then notes they soon will. He explains that the shelter is impenetrable and through his contacts he is one of only a few men that knows that soon a nuclear exchange will occur and most of the world's population will be wiped out. He is safe in his shelter, and wonders if they will be safe as well. The (fake) broadcast goes off and they insist on leaving to see to their families. Radin tells them to drop the pretense but they insist that they would rather die outside than stay with Radin in his shelter. The tycoon explains that they can stay... if they get down on their knees and beg him for forgiveness for humiliating him. Disgusted, they insist they'd rather die with their families, or die with anyone else, or die alone, rather than live at that cost. Radin insists they must be too stupid to leave and gives them one more chance, but they all leave Radin to his fantasy world. Radin rants that it's no fantasy and listens to the fake broadcasts. He screams at the broadcasts to stop and smashes the sound system, but the sirens continue. He sees the explosion on screen and smashes it as well.
Staggering outside, Radin finds the entire world reduced to rubble. He's unaware that the world is unscathed and he's totally enmeshed himself in his fantasy world and thinks he's the last man on Earth.