Two thieves, the Blackbird and West End Bertie, fall in love with the same girl, a French nightclub performer named Fifi. Each man tries to outdo the other to win her heart.
Roscoe writes of his love and announces that he will call on Irene with the ring and ask her parents' consent to their marriage. Father and mother are willing, but decide to give Roscoe a scare before accepting him for a son-in-law. Father assumes a gruff attitude but melts at the right time and Roscoe departs in high glee to prepare for a masked ball at which the engagement is to be announced. Irene jokes him about his size but he warns her that he will fool her by the mystery of his disguise. On the way home in his automobile Roscoe drives over a cliff and is taken to a hospital. There he is, out of his mind, as the guests begin to assemble at the ball.
Mabel tries to sell hot dogs at a car race, but isn't doing a very good job at it. She sets down the box of hot dogs and leaves them for a moment. Charlie finds them and gives them away to the hungry spectators at the track as Mabel frantically tries to find her lost box of hot dogs. Mabel finds out that Charlie has stolen them and sends the police after him. Chaos ensues.
Two rivals for Mabel's hand play a series of dirty tricks on each other. Finally, one of them gets Mabel alone and is about to marry her, but his rival comes up with a strange scheme to stop them. Soon the Keystone Kops arrive on the scene, and chaos quickly ensues.
When a girl delivering expensive garments loses them to some Irish shanty town kids, her boss, a Jewish clothier, is livid and a fight breaks out. Soon the melee spreads to the whole neighborhood with brick throwing merging into bomb throwing, with the sides on clearly ethnic lines.
A new bride has made a batch of biscuits. Her husband pretends to like them, so she delivers the rest to his office. But one bite of these biscuits makes you violently ill, and soon all his visitors (he runs a theatrical booking agency), plus the workmen at home, are ill; when she shows up at the office, they all go after her.