Saw this on a dvd which I own. In fact i own the dvds of all the parts now.
The summary- After the events of Undisputed Redemption, Boyka has found religion. He still fights in the ring but donates most of the profits to the church. He has spent a lot of money to repair his broken knee but events force him to travel back to Russia where he is a wanted convict. This movie is for the fans of the series n fans of Boyka aka Adkins. Martial arts fans will not be disappointed. The fight sequences are frequent and never, ever become tiresome. Scott Adkins once again got into the skin of the character.
The villain, Martyn Ford is an intimidating one with height of 6.8 n weight of 320 lbs. Truly an indomitable n an invincible one.
The plot is a bit lame. The mafia Boss who owns the town n he has his eye on a young n beautiful widow who is in debt.
But who cares. We look forward for this franchise for Boyka's kicks n boy what an awesome fight choreography we get to see in this 4th installment. Isaac Florentine who directed the terrific Undisputed 2 n 3 n Savate didn't direct this one. Inspite of the micro budget, this movie rocks.