It's an engaging story that begins when a corporate headhunter (who moonlights as an art thief) ends up with the wrong client. Roger Brown is a smug executive who lives well beyond his means (to keep his trophy wife happy) and after meeting Claus Greve, his neat little life takes a wild and unexpected turn. Roger becomes a hunted man and the film turns up the violence as his situation becomes more and more outrageous. There are moments of absurd black comedy as well as much bloodshed (and one nasty act of violence against an attack dog) as the film twists and turns it's way to a neatly wrapped up ending.
Askel Hennie stars as Roger and he endures quite a bit in a physically demanding role. Also starring as the cool and calculating Claus Greve, is Nicolaj Coster-Waldau (currently on "Game of Thrones" as Jamie Lannister). The plot continues to thicken and twist as the two stars play a dangerous game of cat and mouse. See it before the inevitable American remake... starring James Spader (if the casting agent has any good sense).