Maisie wouldn’t have gotten involved in Scotland Yard affairs if an undercover policeman hadn’t moved into their house! Not a very skillful policeman, I must admit, the girl saw through him in no time. And since the detectives from Scotland Yard are so incompetent, Maisie is simply obliged to help them. Moreover, the girl herself is interested in what the connection is between her grandmother’s modest boarding house and the famous gang of painting thieves...