Just to get it out of the way: yes, I liked THE GATEHOUSE and I do recommend it for horror fans. There are, however, some unusual characteristics to it that bear mentioning.
It's a little hard to describe, but for the lack of a better term, many of the plot elements are a bit confused or tangled, and some of of the story themes seem quite incongruous, so oddly juxtaposed together as they are.
If you break THE GATEHOUSE down to the bare scaffolding of its plot, the story seems straightforward enough. A single father, Jack, is doing his best to raise his precocious ten-year-old daughter, uniquely named "Eternity". The girl is upbeat and strong-willed but a little odd. For "fun", she likes to dig for treasure with her silly little-girl-sized green bladed spade.
But something dark and sinister is going on in the forest Eternity frequents. People have disappeared, and a dark and horned, and quite menacing, creature seems to be haunting the forest. (Note: for anyone who cares about such details, the horned creature is an unmistakable reference to the Celtic horned god Cernunnos; I was sure you would want to know).
As it turns out, the horned forest God is merely trying to protect what's left of the forest which is under dire threat from a greedy and unscrupulous farmer that's been chopping down large swathes of it. The farmer has been able to do so because he has figured out the system of magic stones that protect the forest and has removed them, effectively disabling the forest's protection system. Jack and Eternity, with a little help from their friends, defeat the evil farmer and return the magic stones to the forest and the forest God, and everybody lives happily ever after.
But within this straightforward plot structure there are a lot of plot elements that feel a little jarring because they don't really seem to fit together in a single story.
Jack, the father and a writer by trade, is under quite a bit of pressure because he's quite low on money and is worried about finances. Still, keeping a stiff upper lip (as this is in Britain), Jack and Eternity are very cheerful and sprinkled throughout THE GATEHOUSE are lots of precocious-and-witty-daughter-bouncing-off-of-slightly-slow-and-bemused-single-father comedic moments. These lend the movie a sort of comedy/mystery air which tends to collide, in my opinion, with the fact that THE GATEHOUSE is actually quite gruesome, and at least half the main characters get blasted with a shotgun (with blood flying everywhere). And there's another scene where Eternity calmly stands before the evil farmer who has been stabbed and currently has an ax sticking out of his back and is holding an empty weapon whilst sitting down and leaning against a tree for support, and says "I hope it hurts" while matter-of-factly and deliberately blowing the farmer's brains out with a flintlock pistol, complete with GIANT 4 foot diameter out-of-the-back-of-the-head spatter of blood and brains. Charming. Not that the farmer didn't have it coming, but still. That's pretty raw. I don't know if murder gets any more blatant than that.
And how about Jack? He's a single father BECAUSE he and his erstwhile wife went paddling about in a boat on a large body of water all the while chugging booze until the both of them were falling down drunk. Clumsily jumping to grab the bottle he has accidentally dropped in the water, Jack accidentally whacks his wife in the head with an oar, knocking her in the water. Jack himself is banged on the head hard enough against the boat to knock him out, and by the time he comes to, there's his dead wife floating in the water who has died calling to him for help. I would've thought that any investigation would've suggested he murdered her with evidence like that. What a charming, responsible fellow Jack is. JUST the type of guy you want raising a ten-year-old girl single-handedly. While still drinking.
And how about that sympathetic forest God? Other user reviews around here have remarked appreciatively about the "positive" depiction of Cernunnos. Did I see the same movie? During the course of the picture, Cernunnos destroys two completely innocent women because they can't produce any of the magic stones he's looking for, especially given the fact that they have no idea what he's talking about and are terrified out of their minds. He turns one poor woman into a 1/2 tree 1/2 woman thing which clearly exists in a state of continuous suffering. And I guess the other woman is a bit more lucky because he just squeezes the life out of her and then quick-rots her almost immediately into little more than bones. Oh yes, he's a real sweetheart.
The entire dénouement of the movie seems to have the characters motivated with confused objectives. All the primary characters set out to "get" Cernunnos, including the evil farmer, but within minutes are trying to save Cernunnos and protect him from the evil farmer. What? In point of fact, Cernunnos, by the end of the picture, has killed twice as many people as the evil farmer and in MUCH more gruesome and painful, drawn-out ways. What's the message here? It's perfectly okay to horribly murder random, innocent women as long as somewhere in your heart you want to save a forest? Has environment worship gone this far?
And the second to final scene borders on the sublimely ridiculous. With the help of Cernunnos, Eternity attempts to give her dad a fine Viking funeral: the old burning boat sendoff. Suddenly, a woman friend of the family who was part of the original "lynch Cernunnos" group and whose daughter has ALSO been blasted with a shotgun, comes staggering up to the shore of the lake where Jack is currently being boat-toasted, and somehow just KNOWS that Jack isn't REALLY dead and starts screaming for him to wake up. Yup... This would be the same Jack who was shot nearly point blank in the chest with a shotgun a little bit ago. Sure enough... Blinking his eyes a little, Jack wakes up and discovers he's on his way to being a crispy critter. Lady friend wades out in the water and collects him. When he's ALREADY awake, we see that Eternity has quietly kept one of the magic stones that were supposedly returned en masse to Cernunnos, and she squeezes it and it starts glowing in her hand. What does that do? Nothing, as far as I can tell. It didn't bring Jack back to life because he was already awake and struggling by the time she pulled it out of her pocket. So what was THAT all about?
I know, I've ripped this movie to pieces, but essentially, if you cover-up one eye and squint the other and just look at the broad strokes, it's not a bad picture. It's just that all the "implementation details" seem to go horribly wrong in an essentially good movie. I think if you're braced for that at the beginning it'll make it a bit more palatable.