I can’t talk TOO much about this without spoiling it – in this case, it’s very much recommended to go in totally blind, which I did, aside from knowing that it was something of a mindbender and had some horror and possibly sci-fi elements.
It all hinges on a young woman on a yachting trip with some acquaintances who ends up in some very unusual, confusing, and horrifying circumstances. It kept me guessing and trying to figure out what was really going on throughout, and it did a good job of laying clues and following up on them later. Every time I thought I had a handle on it (and thought the lead character did, too), it turned out to have another layer.