Boyka is back. This time he is fighting in the first ever inter-prison tournament with one knee.

Russian inmate Boyka, now severely hobbled by the knee injury suffered at the end of Undisputed 2. No longer the feared prison fighter he was, he has declined so far that he is now good only for cleaning toilets. But when a new prison fight tournament begins - an international affair, matching the best fighters from prisons around the globe, enticing them with the promise of freedom for the winner - Boyka must reclaim his dignity and fight for his position in the tournament—Anonymous

Eight elite fighters - prisoners from maximum security prisons around the world - are brought together by a powerful underground gambling syndicate for a secret, survival-of-the-fiercest battle competition. With the odds against him overwhelming, Boyka will take on the syndicate his way and send the whole scheme crashing down around them.—Anonymous