Bob and Jill Lawrence (Leslie Banks and Edna Best) are on a carefree winter holiday in snowy St. Moritz.  With them is their teenage daughter, Betty (Nova Pilbeam).  It is quickly established that Jill Lawrence is a crack shot with a rifle (needless to say, this proves handy later), losing a friendly skeet-shooting match only due to a distraction caused by someone who ought to look like an innocent bystander, except that it's Peter Lorrie, who, we all know by now, is not playing an innocent anything.

          That night Jill is having a bit of fun dancing with someone not her husband, quite in the face of said husband.  She taunts Bob playfully.  All of a sudden there is a small "pop" and the man Jill is dancing with looks down at his bloody shirt to discover that he has been shot.  As the man --a complete stranger to Jill-- collapses to the dance floor, he whispers to Jill that there is a hairbrush in his hotel room.  She is to have this hairbrush taken directly to the British Counsel.  His final words are: "Don't breathe… don't breathe a word to anyone."

          Jill tells Bob of the dying man's request whereupon Bob goes to the man's room, locates the hairbrush and discovers inside the handle a cryptic piece of paper making reference to a locale in England called Wopping and the words: "A. Hall."  Bob barely escapes the room before The Law is upon him.  The authorities want to know why he was in the dead man's room and what the man might have said to Jill before he died.  Later, while Jill is being questioned separately, Bob receives a note, left anonymously at the hotel desk, warning that if Bob or Jill divulge any of what they know they will never see their daughter Betty again.

          The Lawrences clam up and head back to England where they hope to have a better chance of resolving the situation.  After refusing inquiries by the British authorities, who inform the Lawrences that they have stumbled into an assassination plot with major international ramifications, Bob and his friend Clive (Hugh Wakefield) travel up to Wopping in hopes of finding Betty themselves.  There Clive receives some elective dental surgery, discovers that he's what hypnotists call "the highly-suggestible type", and proves himself pretty much useless except that he does manage to put through a call to Jill and head her toward Albert Hall.

          Meanwhile, the villains who kidnapped Betty now have Bob in their clutches.  In a James Bond Moment, the villain, Abbot, (Peter Lorre) graciously explains to Bob the details of his dastardly plan.

          It all culminates in a famous scene at the Albert Hall followed by a Bonnie-and-Clyde style shoot-out that is so much less-ludicrous than Doris Day belting out "Que Sera, Sera" as some kind of child-locating sonar, a device Hitchcock substituted for the shoot-out in his 1956 version of this film.

         [Even today the debate continues as to whether this 1934 film is actually superior to a 1956 remake, made at the height of Hitchcock's career.]

          P.s. It should be noted that Peter Lorre with his performance here sets a high standard for grinning, self-satisfied villainy as the polite, soft-spoken Abbot.