Walter Bedeker is a self-obsessed hypochondriac who calls in his doctor for yet another house call. The doctor says that Bedeker is perfectly healthy despite all the pains that he complains about, and his illnesses are psychosomatic. Bedeker refuses to accept that and complains to his wife, Ethel, and then complains that she's driving him to illness with her gentle whispering. As Ethel ushers the doctor out, he gives her some vitamins and tells Ethel that her husband is one of his healthiest patients.
Ethel returns to close the window for her husband, who accuses her of leaving window opens so he'll die of exposure to germs. Bedeker notices the prescription and first assumes that the doctor is colluding with Ethel. When she explains that they're vitamins for him, he complains that he's dying and she gets vitamins. Bedeker orders her out and she finally leaves. Bedeker asks why a man has to die after such a short relative lifespan, and Ethel goes out. Her husband continues to gripe and a voice chimes in, agreeing with him. A cheery obese man materializes in the room, introduces himself as Cadwallader, and explains that he's been there for some time. He offers Bedeker a bargain: whatever he wants for a microscopic, insignificant item. Bedeker wonders who Cadwallader really is, but the visitor says that it doesn't matter and that what he can give Bedeker is immortality. he finally gets around to admitting that he wants Bedeker's soul, and Bedeker accuses him of being the Devil. Cadwallader cheerfully agrees offer immortality and indestructibility for Bedeker's soul, and says that he won't miss his soul. Bedeker makes sure that there are no tricks, but then asks if his appearance will change. Cadwallader agrees to toss in a no-aging clause, but then tells Bedeker that there's one last clause. Bedeker suspects a trick, but Cadwallader explains that it is an escape clause and, if Bedeker so chooses, he can call upon Cadwallader to end his life with a minimum of fuss. Bedeker says that he would never choose that and signs the contract. Cadwallader produces a flaming stamp and puts his seal on the contract after Bedeker signs it and then disappears.
Bedeker pockets the contract and then goes to the radiator. After a moment's hesitation, he places his hands firmly on the metal but feels no pain and suffers no damage. He tosses out his medicines and Ethel comes in, and her husband says that he's a new man.
Later, Bedeker goes to the subway and stands in line waiting for the train. As it arrives, he jumps onto the tracks and everyone screams in horror. Once the train has gone by, Bedeker gets up, unharmed, and tells the security guard to call the company's insurance adjustor. Soon, Ethel watches as claims adjustors arrive and pay Bedeker settlement fees. Once they leave, Bedeker says that there have been fourteen accident but no thrill, and wonders if Cadwallader has tricked him. He admits to himself that when he was concerned about his health, at least there was some risk. He goes to the medicine cabinet and mixes a cocktail out of various poisons, and then drinks it before Ethel can stop him. Bedeker claims that it tastes like weak lemonade, and explains to Ethel the nature of his deal. She doesn't believe him and Bedeker goes to the roof to jump down the light well just for kicks. Ethel follows and tries to stop him, they struggle, and Ethel falls instead. Bedeker lights a cigarette, wonders if it hurt, and then gets an idea. He goes downstairs, calls the police, and confesses to Ethel's murder.
Later during his trial, Bedeker meets with his defense attorney, Cooper. Cooper complains that Bedeker appears desperate to get convicted and is helping the prosecution. Bedeker is more interested in the fact that he'll be executed by electric chair, and tells his attorney that all the State will get is a staggering electrical bill. He tells Cooper not to bother trying to understand him and leaves.
In the courtroom, the judge informs Bedeker that he has been found guilty. Bedeker isn't interested... until the judge tells him that he's been sentenced to life imprisonment with no chance of parole.
Later, Bedeker is in his cell awaiting transfer to the penitentiary when the guard brings him his last meal. The guard comments that "life" for Bedeker will only be another 40-45 years, and he can do it standing on his head. Once the guard leaves, Cadwallader's voice echoes the comment and he materializes inside the cell, laughing hysterically. Clutching at his ears, Bedeker agrees to exercise his escape clause and falls over dead of a heart attack.