Gilly comes out of prison after serving a six year stretch and decides that he will now turn his life around and go straight. But when he returns to his South London home and visits his old colleague J, in hope of obtaining his share of the proceeds from the job that landed him inside, J soon talks him into getting involved in one last scam.

Every ten years, in an unsuspecting town, The Tournament takes place. A battle royale between 30 of the world's deadliest assassins. The last man standing receives the $10,000,000 cash prize and the title of World's No. 1 Assassin, which itself carries the legendary million dollar-a-bullet price tag.

An elderly ex-serviceman and widower looks to avenge his best friend's murder by doling out his own form of justice.