Forgiving it its very occasional moment of illogical silliness (which is often a very common quality with films of this ilk), this is a well written and well directed grimy little British B-movie that serves to send your heart into your mouth by the end of the first act and keep it there. This film benefits from two utterly superb lead performances by a staggeringly brilliant Kelly Reilly and a fantastic Michael Fassbender, not to mention a surprisingly effective turn from Jack OConnell in the usually-all-too-easy-to-ruin lead villain role. Most importantly though, it has a truly devastating ending that isnt cheaply earned and will linger with you long after the film has finished. A really good British thriller with a horrifically dark spine running through its centre!