Salvadore Ross is a frustrated bitter young man who is involved with social worker Leah Maitland. But she breaks it off when she sees him for what he truly is and believes he'll never change. Her father, a former wheelchair-bound schoolteacher, is a warm caring man who supports her decision but lets her make it on her own rather than telling her what to do. An angry Ross slams his hand into the door, breaking it. He goes to the hospital for treatment and is stuck in a room with an old man with chest congestion.
The old man wryly notes that Ross could easily get over a cold and he's lucky to have a broken hand. Ross jokingly says they should swap and the man just as casually agrees. They go to bed but Ross wakes up in the middle of the night and swings his cast into a dresser...and realizes it's healed. He now has the old man's cough, which is a minor inconvenience for him. The old man realizes he'll never heal a broken hand and asks to trade back, but Ross laughs at him and runs off.
Ross is quick to take advantage of his new-found talent and visits an aging millionaire, Mr. Halpert. He offers him a trade: a million dollars and the man's apartment in return for 46 years of Ross' youth. Halpert is skeptical but agrees and when we next see Ross he's an elderly man. He makes a deal with a young worker at the building, giving him $1,000 for one year of his life. The boy is skeptical but agrees...and promises to set Ross up with his friends for similar deals.
After Ross buys back his youth a year at a time, he goes to visit Leah. But he's the same angry uncaring man as always and Leah overcomes her physical attraction and tells him to get out. She points out that no matter what he's done to improve himself, he has no compassion and she wants a man as good as her father.
Later a clearly changed Ross escorts Leah home. He's gentle and giving, and after dropping Leah off he visits her father and asks for her hand in marriage. He apologizes for his previous behavior and says he's changed. The father refuses, and when Ross asks for compassion, Mr. Maitland says he has none - he sold it to Ross the other day. Then Mr. Maitland pulls out a gun and shoots Ross dead.