The Man Who Knew Too Much 1934

Londoners Bob and Jill Lawrence and their daughter Betty travel to St. Moritz where they partake in some sporting events. Jill enters a skeet shooting contest, and their friend, Frenchman Louis Bernard, a ski jumping competition. While Louis and Jill are on the crowded dance floor together at a party the following evening, there is small popping noise among all the other sounds in the room which ends up being a gunshot fired at Louis. Just before he dies in Jill's arms, Louis vows her to secrecy as to what he is about to say: that there is a brush in his hotel room which she must access using his key and take to the British Consulate. Jill confiding only in Bob who takes the key, he is able to find the brush which contains a cryptic note inside the handle. They also discover that a man in the skeet shooting competition, who they know only as Ramon, also wants the note in the brush, and he and his associates have kidnapped Betty to get it. The Lawrences are warned to say nothing to the authorities or they will kill Betty. Back in London without their daughter, the Lawrences learn directly from the British Foreign Office that Louis worked as a spy for them, his latest case being about an upcoming assassination attempt on a high ranking foreign official. The piece of paper in the brush is probably the key to finding out the assassination plans, and a successful attempt could spark a war between countries. Bob and Jill believe that the piece of paper, which they refuse to turn over, is what is keeping Betty alive. As such, the Lawrences have to decide how much investigation to do on their own with their loyal friend Clive and how much to involve the Foreign Office in their primary mission to save Betty, with thwarting the assassination a bonus if they are able.