Lord and Lady Algy separate on cordial terms, after he breaks his promise not to gamble again on the horses. When the wife of soap magnate Brabazon Tudway, is courted by Algy's philandering elder brother, Algy tries to help his brother escape Tudway's wrath by hiding Mrs. Tudway in his apartments. Tudway discovers her there and is about to accuse Algy when Lady Algy appears and, believing Algy to be innocent, tells Tudway that his wife was there to meet her. Although Algy and his jockey disgrace Lady Algy by getting drunk at a masked ball on the eve of the Grand Derby, the race in which Algy plans to stake his entire fortune on his pet racehorse, Lady Algy saves his fortune by betting her own money on a dark horse that wins. Algy know penitent, swears he will give up gambling forever, thus reuniting with his loving wife.