Four identical plaid suitcases cause trouble to their owners when they all stay at the same hotel. The first case is full of jewels belonging to the wealthy Mrs. Van Hoskins, who wants to put...

Four identical plaid suitcases cause trouble to their owners when they all stay at the same hotel. The first case is full of jewels belonging to the wealthy Mrs. Van Hoskins, who wants to put them in the hotel's safe and is unaware the staff wants to steal it, while the second case is full of documents and belongs to Mr. Jones, an agent for the government who is trying to get it back from Mr. Smith, who is trying to expose its contents to the public. The owner of the third case is Dr. Howard Bannister, a musicologist engaged to Eunice Burns and is trying to get funding for his igneous rocks theory by Dr. Frederick Larrabee, but his life is turned upside-down when he meets the owner of the fourth case, Judy Maxwell, an intelligent young woman attracted to Howard and with a tendency to accidentally cause trouble wherever she goes. Judy passes herself off as Eunice and wins over Mr. Larrabee's approval, but the other finalist vying for Larrabee's funding, Hugh Simon, discovers the truth about Judy, just as the suitcases get mixed up and disaster ensues.