Like the best COLUMBO episodes, THE SNORKEL opens with an elaborate, ingenious murder being committed by a cold, brilliant man.
Paul Decker (Peter Van Eyck) drugs his wife, plugs the cracks in the doors and windows, opens the gas jets operating the room’s lamps, and watches her succumb to the fumes while he sits calmly wearing a snorkel with rubber tubes that feed him fresh air from outdoors. The next morning, he crawls beneath the floorboards through a hidden trapdoor and listens to the investigating detective (Gregoire Aslan) and an official from the British consulate (William Franklyn) declare the death a suicide.
But Candy (Mandy Miller) knows better. She knows her stepfather Paul has murdered her mother, because she saw him murder her father years earlier. Nobody believed her then, and nobody, not even her governess Jean (Betta St. John), believes Paul is a murderer now.
Peter Myers and Jimmy Sangster’s tightly constructed screenplay turns into a bit of cat-and-mouse, as Candy starts to figure out how Paul, who claims to have been in another country at the time of the suicide and has the passport stamp to prove it, could have done the murder, and he realizes she’s beginning to figure it out.
The only Hammer film for both Van Eyck and director Guy Green, THE SNORKEL rests upon their more-than-capable work, wringing as much suspense as possible out of the concept (which was hatched by DR. NO actor Anthony Dawson). Van Eyck plays Decker like a real creep, particularly a scene in which he reads Candy a fake suicide note allegedly penned by her mother.
Unfortunately, Miller’s performance—the film’s most important—is not up to Van Eyck’s, and she seems a bit old for the role too. It isn’t a fatal misstep, however, and THE SNORKEL is a delightful thriller with a thoroughly hissable villain.