เรื่องย่อ : 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.