RITCHIE DONOVAN is a professional thief whose luck has just run out. The only survivor from a heist that goes terribly wrong, RITCHIE is forced to take the rap and sent to Russia to steal a priceless antique cross locked in a safe on the penthouse floor of a Moscow skyscraper.
Things start badly and go rapidly downhill. RITCHIE'S psychotic Russian accomplices, PETER and YURI, kill a woman during the robbery and they are forced to take hostages when trapped by the police on the unused 13th floor. It gets worse. During a hostage hand-over the hostage ends up without a head, and RITCHIE realises that it's not the police he's dealing with it's something much more terrible.
And worse. The hostages, led by a deluded ex-army commando, BORIS, decide to make a stand. In the ensuing confusion one of the hostages, SONYA, gets a gun and takes control, killing PETER. She is a religious fanatic with her own agenda on how to deal with the situation and it doesn't involve the police, but it does involve taking RITCHIE hostage.
And even worse, SONYA is in fact the psychotic twin sister of the KILLER who was responsible for the earlier beheading. They're descended from Ivan The Terrible and are continuing his good work. Killing is their 9-5 job, but just this once they're willing to do overtime.
Worse still. Now teamed up with the other hostages, RITCHIE manages to get free but can't escape as the lift entrance is blocked off. They find the KILLER'S bedroom and following an incident with a fridge and human body-parts one of the hostages, DMITRY, flips and turns from coward to hero (think the Lion in The Wizard of Oz, but in a really bad way). He teams up with BORIS and they decide to go hunting the serial killer. RITCHIE discovers that PETER stole the cross from him before he was shot, so even if he were to get out he'd be killed immediately for screwing up another job.
To recap: RITCHIE is not only locked in a building with the insane descendents of Ivan The Terrible but is also unable to even attempt escape until he retrieves the cross that he took from them. At the same time, BORIS, the ex-commando, and DMITRY, the journalist turned Rambo, have decided to play the KILLER at his own game and are setting up a trap that can only end badly for everyone involved.
You'd think this was as bad as it could get but for RITCHIE to escape with his life he will have to pull a hostage's ear off, survive a stabbing from the partner he thought was dead, share a kiss under a pile of dead bodies, fight the KILLER (and his sister), and last but not least, somehow turn a rat into a makeshift bomb.
And you thought you were unlucky?