It's a black-and-white Hammer suspense film. You could call it horror if you wanted, but it's on the borderline. It has no monsters and no supernatural, but simply some greedy people in a house that's worth a lot of money.
Its most famous actors are Andre Morell as the evil old grouch who's the head of the house and Barbara Shelley as the nice one in the family. The film begins with Catherine Lacey reading Edgar Allan Poe aloud, at which she's rather good. Don't get too attached to her, though. She's written a will cutting her husband (Morell) out of her inheritance, so barely two minutes of screen time have elapsed before she's being dragged outside and having earth shovelled on her.
One of the more unusual things about this film, incidentally, is that it reverses the usual pattern of this genre. Morell isn't a lone psycho, unsuspected by everyone except the heroine. On the contrary, he's too old and feeble for any rough stuff and so he entrusts all that to the servants. He has two and they're both in on it. In other words, the entire household either murdered Lacey personally or is completely okay with it and is helping Morell cover it up.
Everyone except Lacey's cat, that is. This is the kind of cat that only exists in movies, with the loyalty of a dog and the thirst for revenge of the Count of Monte Cristo. It loved its mistress and it hates her murderers like poison. It's only a cat, of course. It shouldn't be a threat to anyone of healthy body and mind. However that's the point. Morell and his servants are so twisted and steeped in sin that they get almost hysterical in their desire to hunt down and kill the cat, even going so far as to offer money to three vile relatives who make Morell look almost sympathetic. One recently did two years in jail, for instance. "Now I've got that off my chest, I can pretend that you're human beings."
Even the environment is dangerous, which might prove useful should the script ever be looking for ways in which bad people can come to bad ends. There are rats in the cellar, dangerous swamps in the woods and a top storey with rotten floorboards. Oh, and one of the biggest threats to Morell's life is his own temper. "Calm down, Walter. You'll work yourself up into one of your attacks."
There are nice people too. Barbara Shelley is, for instance. Essentially, though, this is a story of villains who could quite easily get into the habit of murder, rather liking it as a solution for all problems. You know they won't win, though, because they're also unintelligent, superstitious and incapable of agreeing to come in out of the rain. They're outwitted by a cat. Repeatedly. This is a film that probably wouldn't have been significantly different had it been made in any of the three preceding decades. (That's a compliment.) It doesn't need special effects, or anything except a repertory company of British actors shut away with each other and their feeble consciences.
Morell's good. He's normally such an avuncular sweetie that it took me a moment to get my head around this evil, savage incarnation of him, but he sells it well. Barbara Shelley is all-important, surprisingly. She takes control of what could have been an insipid "damsel in distress" role and makes herself the assertive lynchpin of the movie. The whole cast's good, though. They also include Mr Range from Frontios and Temmosus from The Daleks.
This isn't a brilliant movie. It's just a pretty good one. It doesn't manage to give its cat quite as much screen presence as it was probably hoping to, but there's still more than enough to fuel the film. The important thing is the humans, anyway, and they're all juicy and watchable.