This is a revenge story, actually a couple of them that are intertwined. It's from the director of the original Girl With the Dragon Tattoo. It follows Victor, a henchmen for the mob and his neighbor Beatrice. One day Beatrice confronts Victor with some incriminating footage of him killing someone. All she wants in return is for him to kill someone else.
That's what the plot seems like, but it goes far deeper for both of them and I don't want to spoil it. I will say that this was surprisingly a very good revenge story and very well acted by both Colin Farrel and Noomi Rapace.
Quality movie, one of the better movies out right now in this slow film season.