Bea (Rose Leslie: Game of Thrones) and Paul (Harry Treadaway: The Lone Ranger) are two crazy kids in love, just married, and embarking on their honeymoon in a remote cabin in the woods in upstate New York. But it all almost instantly goes bad, when — after an encounter with a weird, possibly violent ex — Bea goes a-sleepwalking out in the forest in the middle of the night, and the next day starts behaving very oddly. Writer (with Phil Graziadei) and director Leigh Janiak, making her feature debut, drops in lots of tropes that will speak to in-the-know genre fans — those strange lights in the woods and Bea’s missing time are classic signs of an alien abduction! — and clues that maybe whatever is going on with Bea extends back to long before she ever met Paul; did she have a more nefarious motive for bringing him to this place, which has been in her family for many years, than simply showing him a piece of her childhood? Janiak brings a sure visual hand to the oversaturated horror-in-the-woods subgenre — Honeymoon is very effective in creating an unsettling mood — but it’s all too-slow build-up leading to a too-rushed payoff that is crying out for more examination. Leslie and Treadaway are wonderful, together and separately, as they cope with weird scary events that serve as a disturbing collective metaphor for newlywed life, but just when that metaphor comes to its fore is when the film pulls away. As is so often the case with movies that broach the horrific and the fantastical, Honeymoon ends, frustratingly, just when it could have gotten really intriguing.