In a snowy Montreal, a chauffeur with a French accent and a magnificent raccoon coat delivers a message to the home of wealthy jeweler Balsac. A snooty butler (Alexander Frazer) reminds him bluntly of the existence of a servants' entrance, then tells him he may wait where he is (after instructing him to remove his cap). The chauffeur complies in silence.~Balsac (Julian Gray) is in the middle of telling his daughter's suitor, John Sommerset (Kenneth Duncan), that, far from getting engaged, they must break off their relationship, even if Sommerset is secretary to the Governor General. Balsac declines at first to read the message. When he does finally elect to read the note, he abruptly takes his leave and enters the waiting car. The chauffeur, meanwhile, has pilfered a few cigars. Outside, a man asks two policemen for a light. (Though the film is clearly set in Montreal, the policemen wear the familiar uniform of the British bobby, complete with the distinctive helmet, a garb never worn by the Montreal police force.) The man's accent could be from the Balkans or the Scottish Highlands. This is our introduction to Ivanov (George A. Temple). To the sound of sirens we discover Balsac in the now-abandoned car, a bullet through his head.~Inspector Vernon (Roland Drew) of the Criminal Investigation Division (CID) informs Balsac's daughter Yvonne (Doris Covert) of her father's demise and sends Detective Sergeant Williams (Arthur Stenning), a bumbling detective, to interview the servants. After establishing that the daughter is not aware of her father having any enemies, Vernon dismisses the young couple. Once alone, he helps himself to a generous belt of Balsac's scotch. At headquarters, Vernon interviews the butler but learns nothing. The butler, back at the house, opens a safe to remove jewels and documents. A waiting intruder whose face we never see strangles the butler and heaves his body out of the window. Vernon now interviews Ivanov, who claims to be the lover of the maid, Toinette (Miriam Battista), and also claims to be employed at the Mount Royal Hotel. Toinette corroborates his story. Cornelia Du Play (Ruth Roland), a longtime acquaintance of Balsac, shows up at his office, conveniently located in the Mount Royal Hotel, and asks to see his latest acquisition, the extremely valuable Lavretsky collection of precious stones.~After she has upset a tray of gems, a particularly precious specimen is found to be missing. Vernon, who just happens to be in the building, is summoned. Du Play is released after only a perfunctory search. Sommerset receives a blackmail letter: someone has discovered that when Balsac married Yvonne's mother, his first wife was still alive - a fact unknown to Balsac.~Yvonne is thus the issue of a bigamous marriage. The ubiquitous Toinette eavesdrops at every possible opportunity. International jewel thief Schubin (Eugene Sigaloff) and his wife Gruschenka are also in the hotel. Toinette enters their room to accuse them of double-crossing her and her partner Ivanov, complaining that the blackmail plot was not part of their agreed plan. Knowing that Schubin shot Balsac and that Ivanov killed the butler, Toinette threatens to turn state's evidence to save herself. The impulsive Gruschenka shoots Toinette. The pair take her body to Du Play's room in the Mount Royal Hotel and dump it on the bed while an oblivious Du Play sings in her bath. Williams comes in to arrest Du Play but she knocks him out with a flatiron. Meanwhile, Sommerset makes his way to a dingy café bearing an envelope containing money provided by Vernon that is intended for the blackmailers. There a waitress instructs him to go to a flower shop located (where else?) in the Mount Royal Hotel. Du Play meanwhile heads to Schubin's room and proposes to buy the now slightly depleted Lavretsky collection.~Ivanov arrives, followed by the police, and is chased onto the roof where he is shot. Schubin and Gruschenka are arrested along with Du Play. However, Du Play is quickly released when it is revealed that she is a private investigator working for an American agency (the Jewellers' Protective
Association) while her parrot endlessly squawks, "Trouble, nothing but trouble," when not suggesting it is time for cocktails. <61mn 45s>