Mason only knows one way to fight – to the bitter end.

Army veteran Mason Sharpe is finally enjoying some peace and quiet. Sleepy days full of good music, better barbeque, and lazy rides on his motorcycle.

But then he sees three burly men beating on a kid and knows he has to step in.

The kid, Spencer, is obsessed with the idea of winning big money at an underground fight club – he desperately needs the cash to fund a life-saving operation for his little sister.

Mason takes one look at Spencer and strongly advises against getting into the ring.

But Spencer doesn’t listen and signs up to fight anyway. Badly injured, he ends up in a hospital – just another victim of the brutal motorcycle gang who run the fight club.

Mason can see they’re taking advantage of Spencer, using him as cannon fodder. He thinks maybe he can win the money for Spencer’s kid sister – and rain down a little pain on the bikers while he’s at it.

So Mason climbs into the ring – and sets off an escalating war with the vicious biker gang. A war that can only end one way – Knock Out.