C.C. "Bud" Baxter (Jack Lemmon) has two valuable assets, an upper west side apartment conveniently located to work and an accommodating nature. He routinely vacates the apartment for company executives and their mistresses. Bud has been rewarded with a speedy climb to the executive ranks, but he is unhappy with how he has achieved this success. On Christmas Eve, Bud returns home to find one of the boss’s women, Fran Kubelik (Shirley MacLaine), passed out in his bed after attempting suicide. Fran is an elevator operator who had been promised marriage, but instead was cast aside when the boss’s wife returned from vacation. With the help of a neighbor who is a doctor, Bud nurses Fran back to health. Romance and redemption for the pair follow.