If Midsummer was Finnish and horny.
Midsummer is pretty horny, but nothing compared to this movie. It is atmospheric and deeply unsettling, very creepy and occasionally pretty scary. I enjoyed it a lot. The casting is wonderful, and the limited effects are put to great use, relying more on strength of characters and performances than on visual effects. I recommend this to anyone who wants to learn why you should never go on couples retreats, for people who don't want to go on vacations in Finland, and to anyone who thinks that hanging out with other couples is the worst.