This is the third undisputed film and in my eyes the best, The film picks up several years after the Yuri Boyka's fight with George "The Iceman" Chambers. Boyka, humbled and resigned to his fate inside the prison system, has become the facility janitor and spends time mopping the hallways and sewage system. Due to his nearly crippling knee injury from his fight with Chambers, he has taken solace in religion and tried to ignore fighting--the one thing that he really loves--altogether. His former manager has begun to expand his previous enterprise of prison tournaments to extend the first ever inter-prison competition, gathering the best prison fighters from around the globe to compete for a chance at a cleared record and early release. As Boyka hears the preliminaries taking place within his prison, as well as failing in his parole, he begins training privately to bring his knee back into fighting shape. Just when the prison champion is declared, Boyka challenges him on the spot, which both the warden and his former manager, Gaga, agree to out of mutual respect and a belief that Boyka is attempting suicide and wants to die with dignity. When he easily defeats the current prison champion, they enter him as a longshot in the inter-prison tournament, the inter-prison tournament consistence of Eight incarcerated brawlers compete for their freedom in an underground fight to the death funded by a powerful underground gambling ring. Boyka (Scott Adkins) works his way up through the ranks, the more powerful his opponents become. Upon realizing that his mysterious benefactors have no intentions of letting the winner reap their reward, Boyka launches into a fierce battle to bring the crooked syndicate crumbling to the ground, and expose their inhumanity in the process!