In the fourth installment of the fighting franchise, Boyka is shooting for the big leagues when an accidental death in the ring makes him question everything he stands for.

After eight years since the events of the first film, a scientist has designed a new species of bat genetically designed to be biological weapons in a confrontation between Chechen and Americans.

An ex-special forces operative wages a one man war through the streets of Amsterdam to rescue his friend's daughter from the local crime syndicate.