This is one of the more bizarre movies I've ever seen, and that's saying quite a bit. As the blurb tells us, a group of rough-and-tumble college kids are out clubbing on Christmas Eve when they're persuaded to spend the holiday at the country house of a pretty girl; after getting ejected for a bar fight, they all pile into a car and off they go. Horror movie tropes tell us this isn't going to end well, of course, which is what keeps us at least mildly interested.
I won't say much more about the plot, as it's fairly self-explanatory as you watch things unfold (although the writers/directors don't seem to worry too much about making things make sense to the viewers - there's no backstory or explanation about the strange, creepy fringe characters, but perhaps it's not necessary). Vincent Cassel is nearly unrecognizable as Joseph, the insane-right-off-the-bat gardener, especially compared to some of his more recent roles (I'm thinking his suave, sexy ballet master in "Black Swan," or his Russian gangster in "Eastern Promises," for example), and he really makes this movie all on his own. His strange obsession with Bart, one of the college boys, is quite disturbing to watch, especially once we find out what his true intentions really are. You can't help but perk up with interest, dread and morbid fascination every time Crazy Gardener Joseph is on screen.
All in all: Not a great movie by any stretch, but passable as a creepy horror film, and Cassel is THE reason to see it. If you're already a fan of his, put this in your rental queue. If you're not, this role may repulse you enough to never want to watch him in anything else!