Caveat

 Isaac (Johnathan French) is recovering from an accident that made him lose some of his memory when Moe (Ben Caplan), a friend, offers him some money to go look after his niece Olga (Leila Sykes).

 The first caveat is that the girl lives alone in a remote, nearly uninhabited island. Her mother's gone missing, and she needs someone around because she suffers from some sort seizures that leave her catatonic for a while. The other, slightly major caveat is that Isaac is forced to wear a sort of leather harness chained to a flagstone in the basement that severely restricts his movement around the house. Moe insists that Olga will not allow him to stay in the house otherwise, but it's still a bit of a dick move to spring that at the very last minute; That guy's probably up to no good.

 Olga, when she's not under a catatonic spell, wanders around with a crossbow (which she explains she uses to hunt foxes). She mentions that her mother was quite mad before going missing, and that her dad killed himself when he got locked up in the attic (he shot himself out of extreme claustrophobia).

 For a while Isaac wanders around the house's dilapidated halls and rooms, experiencing mild hauntings of the sort that just might have a non-horror movie explanation. But then he finds a creepy-ass clockwork rabbit with bulging eyes that acts as a dowsing rod but for scary shit, and it helps him find the missing mother's corpse immured in the cellar.

 He confronts Olga about it, and things get a bit complicated - the mystery hinges on some of his lost memories, and as things develop he's forced to fight for his life to escape a tiny conspiracy that keeps shifting shapes as new events come to light.

 The pacing is a bit glacial, but that goes with its 'modern gothic' subgenre; A little too slow in parts, but it methodically builds up towards some very effective (non-jump-) scares. The requisite atmosphere is strong, thanks to some great work from cinematographer Kieran Fitzgerald and a very solid production design (that rabbit, crafted by Lisa Zagone, is a fucked-up wonder). It's an impressively realized, very focused low-budget production.

 Writer/director Damian Mc Carthy keeps his cards close to his chest at all times, giving out morsels of information with very little exposition to go with them. It's never arbitrary, though - there's a strong sense that there's a solid explanation for everything that's going on, including the seemingly supernatural events; Just what that explanation is, though, may vary from person to person.
 I'm still poking at it, trying to figure out this or that, the exact way its elements hang together - Caveat lingers in the imagination, and that's an unequivocal sign of success.