This film is Bad in a lot of ways—the plot is riddled with holes, the acting is often overdone, the day-for-night shots are some of the worst I've ever seen. But there's something here, if you dig for it—not a horror story about a werewolf so much as a horror story about a very rich man who destroys everything around him.
Tom Newcliffe is a man with a goal and no regard for limits, and the film's initial framing of him as a daring leader is torn to pieces by the rest of the plot. He brings together a bunch of people who have variously tenuous connections to lycanthropy and simply declares that exactly one of them must be a werewolf. This is nonsense—he could be wrong about all of them, or right about multiple—and it's where the film's credibility as an intricate mystery for the viewer to solve begins to fall apart. But if you're willing to read this instead as Tom's own willingness to throw reason aside in his monomaniacal pursuit of the glory of the hunt, the film takes on a new, more interesting character.
By the rules outlined in the film, a werewolf's transformation is triggered only when the full moon is out and they're exposed to wolfsbane pollen—something explicitly stated not to be native to Britain. If there is a werewolf in the house, they are a werewolf in remission... someone who discovered their lethal ailment and retreated to an island where they and those around them could be safe. It's only Tom's reckless action of bringing them together and exposing them to the trigger that makes them a danger.
All the blood in the film is on Tom's hands. His lust for the hunt, for domination, is what kills everyone around him... the wolf is just his weapon, wielded as carelessly as you'd expect from someone who sees himself as a higher form of being than everyone around him by virtue of his wealth. From this angle, despite its rough edges, I think this film actually has something pretty interesting to say.
