Jack Denham, an orphan, is adopted by his aunt, Mary Watkins, a wealthy spinster, who is known to everybody as "'Aunt Mary." Aunt Mary's sweetheart receives an offer of a position in the city, which he gladly accepts, as he has grown tired of Aunt Mary and seizes this opportunity to desert her. A number of years elapses and he never returns. When Jack reaches his majority Aunt Mary sends him to college, and she is left alone with her two servants, Lucinda and Joshua. At college Jack has three chums, Burnett, Mitchell and Clover. Jack is expelled from college for breaking the rules. Aunt Mary writes her lawyer, Mr. Stebbins, to look after Jack. Jack is despondent and goes to a cabaret show, where he meets "the girl from Kalamazoo." While under the influence of liquor he proposes marriage and gives her a ring he is wearing. Jack returns to his hotel and does not miss the ring till the next morning, when the girl from Kalamazoo telephones him and he realizes what a fine scrape he is in. Jack's chums try to cheer him up and they all go to a saloon and have several drinks. Mitchell has a small pistol which he is showing to the boys, and Jack examines it. He shoots at a dog and accidentally hits the bartender. Jack is threatened with arrest. He telephones Stebbins, who pays damages of $100, and Jack is allowed to go. Stebbins induces Jack to return to Aunt Mary and tell her the story himself. Aunt Mary greets Jack affectionately and tells him she will forgive everything as long as he never wrongs a woman. Stebbins arrives with the news of a breach of promise suit against Jack, brought by the girl from Kalamazoo. This angers Aunt Mary and she disinherits Jack. The girl from Kalamazoo learns that Jack has been disinherited. She goes to see Aunt Mary and tells her that she really loves Jack and does not want his money. Bob Burnett now comes to Jack's rescue and insists that Jack stop with him at his home for a while. While at Burnett's Jack falls in love with Betty, Bob's sister. Mitchell plans to gain Aunt Mary's sympathy and telegraphs her that Jack has a bad attack of measles. Aunt Mary decides to go to her nephew at once. The boys are in the midst of a surprise party, given in honor of Betty's birthday, when Mitchell receives a telegram from Aunt Mary stating she is on her way. This throws Jack and the boys into a panic as Aunt Mary is due to arrive. Betty saves the situation by declaring that she will say the telegram was a trick to bring Aunt Mary to a party in her honor, and she will help the deception along by posing as the housemaid, Janice. Aunt Mary arrives and her rejuvenation begins. Betty dresses her hair in the latest Parisian style, and lends her one of her evening gowns. Aunt Mary, who has been led to believe that the party is in her honor, enters into the spirit of the occasion and has a glorious time. The boys order an automobile and take her for a trip around San Francisco. Aunt Mary is delighted with the trip. They go to a cabaret and the boys induce Aunt Mary to dance. Betty at home finds a newspaper in which is an article stating that Jack is being sued by the girl from Kalamazoo for breach of promise, and this puts him in bad with Betty. The girl from Kalamazoo notifies Aunt Marv that she is very ill. Aunt Mary and Betty go to see her, and Aunt Mary gives the girl enough money to take her home as soon as she is able to travel. Aunt Mary, having had enough of gay life, decides to return home. She reaches her home, and being dissatisfied with Lucinda as a maid, sends for Betty. Betty is very much amused when she receives the letter, and decides to go to Aunt Mary's for a while. The girl from Kalamazoo recovers and makes arrangements to return to her home. She is deeply grateful to Aunt Mary for her kindness and stops off to say good-bye to her. She meets Betty and confesses that she had no claim on Jack. Jack goes to Aunt Mary's to make a last appeal to Betty. Aunt Mary learns that Betty is Bob's sister. Betty and Jack ask Aunt Mary for her consent to their marriage, which she cheerfully gives, and they all look forward to a very happy future.