In other words, it's Lovecraft tropes adopted in a bit of a bait'n'switch.
Upon arrival to Dunwich Island they're nearly immediately accosted by Oliver Reed and his band of merry idiots, overacting some juvenile irresponsibility. His characterization is all acting drunk and wearing tight pants. He must've been a wearisome man to have to put up with if he was anything like the role here. He's all about making faces and threatening rape. This bunch of inbred island-folk don't exactly roll out the welcome mat for long-lost daughter Susannah. Uncle Zubulon does his best to shoo 'em off, showing off a maimed compatriot. We already know there's something in a pitiful cabin locked behind a red and fancy door. As the isle seems populated solely with man-children and utter douchebags, whatever is behind there already seems more appealing than they are.Anyhow, no one's very interested in Susannah claiming her property, not Ethan (Reed) nor Aunt Agatha (Dame Flora Robson). Old, patronizing, paternal hubby only seems to have one personality trait, "bemused," when dealing with young, fresh Lynley. He doesn't seem flexible enough to put up with the cobwebbed, dusty rattrap she's inherited. They're immediately dragged out by "Rapey Reed" to go see Aunt Agatha in her even less appealing watchtower home. She tells 'em that Susannah was sent away so as not to be affected by the Whatley curse. I assume it means she was sent away so as not to turn into a magnificent jackass. Aunt Aggie proves her jerkiness by going out of her way to tell Susannah how horribly her parents died.
For all this running around, they've had a pretty full day. Seems like the only sensible thing to do is unpack and stay in the big, nasty, ramshackle old mill that everyone has told them to get away from as soon as possible. Even more, it's already been proven that the island is populated exclusively with assholes. Anyone smart would head back to the mainland and sanity. Instead, Mike takes off and Susannah wanders around, taking a trip down a very cruddy memory lane. We know she shouldn't be there alone, and everyone in the movie knows she shouldn't be there alone, but Mike and Susannah? Dipshits.
