Ronnie Thompson, James Nunn
James Harris, Mark Lane, SC Films International
Jack O'Connell, Sheridan Smith, Ralph Brown, Russell Tovey
"Serenity House", or Tower Block 31 as it's called in the blueprints, has seen better days. It's scheduled for demolition as soon as the council can rehouse everyone. Most of the other blocks in the area have already been demolished, and the neighbouring block is already empty. This one has been emptied floor by floor, with only the 10th floor occupants to go. But getting rehoused takes time, and they've been waiting for a while. The property developer who bought the land is getting impatient, but there's nothing he can do.
While they're waiting to get rehoused, a local youth is beaten to death in the stairwell. None of the 10th floor residents saw anything, and it's just another sad reminder of why the area needs to be redeveloped.
Two weeks later, life carries on as normal for the residents: Becky, a young woman who has just come out of a bad relationship, Neville and Violet, the pensioners who remember when this used to be a nice area, the Buxtons, whose marriage is falling apart, Kurtis, the violent thug who demands "protection money" from everyone on his floor, the Bannister family, struggling to make ends meet, Jenny, the loud drunk with two kids, Paul, the creepy loner, and Mark and Gary, the two drug dealers.
But suddenly their lives are shattered by automatic gunfire from a high calibre, silenced sniper rifle. Someone is in the opposite, abandoned building, shooting at them. Someone who is a very, very good shot. He could come in and kill them easily, but clearly wants to make them suffer first. If they pass a door or window, they get shot. If they try to leave, they get shot. They're trapped inside the building, until they starve or he shoots them. The phones and internet are cut off, the mobiles are being jammed. Thanks to the isolated area, nobody has heard the silenced shots or the screams.
No help is coming. There's no way out. And the mysterious sniper seems hell bent on killing all of them. One by one.