A student film-crew are out shooting footage about an apparent bear-poacher in the remote Norwegian wilderness. They suspect Hans (Jespersen), due to his suspicious behaviour, and follow him from his caravan on one of his night-time excursions. To their amazement and shock, they discover that, while he is a hunter, it's not bears that are his prey: he is the titular troll-slayer. More than that, he has been officially sanctioned by the government, who are entirely aware of the situation, and empowered to take care of these legendary beasts, whenever they stray off their territory and start posing a threat to people or livestock. Hans, with the crew in tow, tries to find out the reason bebund the sudden surge in such reports, and eventually discovers the cause is a Jotnar, a monstrous beast 200 feet tall. However, one of the students was injured during an encounter, and is beginning to feel the worse for wear.
There's a lot to like here, starting with the way the makers realize that "found footage" does not have to mean "shot by an epileptic octopus"; the great majority of this is admirably coherent. The effects, while obviously done on a budget, mesh with the footage amazingly well, and I liked the way the trolls look exactly like they've sprung to life from the pages of a story-book, with no real attempt to make them biologically plausible [the inverse-square law would leave them incapable of walking]. However, the pacing is off, especially given a title which lays it all out there: while they are worth the wait, it takes too long to get to the trolls, and outside of Hans, the rest of the characters are so hardly developed at all, they might as well not have been present. Still, this is clearly much more about the monsters, rather than the humans, and on that basis, it delivers everything you could want, with a perfectly straight face.