My God, this is nasty, but it's also horribly gripping. Tom Shankland's feature debut hits the ground running with an atmosphere of moral and physical rot learnt from Se7en, and a twisted psychotic revenge plot all of its own.
Bodies are turning up in a city of permanent night (New York, but unnamed), some viciously mutilated, some with a scientific equation, W?Z, carved into their skin. The casting is perhaps the most interesting thing: Stellan Skarsgard plays a cop with a guilty secret, Melissa George his rookie partner, while smaller roles are taken by Ashley Walters, Tom Hardy and Paul Kaye.
The rationale of the killer makes for a gruelling watch, and you might recommend that writer Clive Bradley undertake psychiatric counselling, but its cumulative effect is unarguable.