East Side boy Peter Mullaney longs to become a policeman. He goes to the training school but is turned down because he is not up to the standard of height, until he demonstrates his prowess by knocking down a big bully. The Commissioner, who has high ideas of the necessary mental equipment to improve the force, gives him a chance if he rates high in the written examination. He misses one question and is turned down, but begs permission to wear the uniform one night, in order not to disappoint his sweetheart, Judy. His chance comes when burglars invade a house and shoot his friend Officer Gaffney. Peter knocks both out but lands in a hospital himself. When he recovers, the Commissioner pins a policeman’s shield on him, and he declares his love for Judy.