-
Mary Holmes and Frank Jordon are sweethearts. Mary tells Frank that she is going to have a birthday party and wants him to invite some of his boyfriends. Madge Jordon is a pupil at Miss Fish's seminary. She receives an invitation to Mary's party, but not being able to get away, she sends herself a telegram, supposedly from her mother, saying that her brother is very ill. In the meantime Frank Jordon sends a letter to his friend, Jimmie Marsden, inviting him to come to the party and to bring his clothes with him, as Frank's house is next door to Mary's. Madge is permitted to leave the school and starts away with a suitcase, on which are the initials "M.J." Jimmie Marsden sets forth with his suit case, which is painted with his initials, "J.M." They meet on a streetcar. When they get off, by mistake they take each other's suitcases. Two crooks rob Jack, who afterward notifies the police, telling them of the robbery of his suitcase. In the meantime Miss Fish, the school principal 'phones Madge's mother to inquire about the supposed sick brother and learns that no one is ill. Fearing that the telegram was a hoax to lure Madge from the school, she 'phones the police and tells them that Madge can be identified by the suitcase with her initials on. Jimmie captures the thieves who are brought to the police station. When the suitcase is opened and the girl's clothes fall out he is immediately held for attempted kidnapping and thrown into a cell with the crooks. Frank Jordon comes to his assistance and is given the suitcase by the police. He starts out and meets Miss Fish, the school principal, who has him arrested for the kidnapping. In the interim Madge, who has brought Jimmie's suitcase to the party, discovers her mistake, but for a lark puts on a suit of his clothes. Jimmie gets out of jail, leaving Frank in his place. The latter decides to get even. From Frank's window Jimmie looks into Mary's house and thinks he sees a man there, who is in reality. Madge dressed in Jimmie's clothes. Frank 'phones his mother from the jail that he is held for kidnapping, but that the guilty party is in his room. Jimmie puts on Frank's dress suit to attend the party. Several other complications ensue, ending with everybody arriving at the police station, where the exchange of the suitcases is explained and the mystery straightened out.
—Moving Picture World synopsis