When the rich uncle finds the bride in the company of one of her former suitors, he mistakes him for the bridegroom.

Aging roué Arthur Merrill meets flapper Penelope Stevens on an ocean liner and decides to undergo rejuvenation surgery so that he may enjoy life again. Transformed, he attends a wild jazz party given by Penelope and persuades her to visit his apartment, but he finds that she is a "good girl" and only flirting. After he gives Penelope a scare and a lecture, her old beau, Brock Farley, enters with a letter to Arthur that reveals Brock to be his son. Arthur gladly steps aside, renounces his wild living, and returns to a simple life.