Slum doctor Leo possesses the Alpha gene serum. His ex-fiancée, Valerie, desiring to seize the serum, dispatches assassins to besiege his clinic. During his escape, Leo stumbles upon Serena, who is also being hunted. In a desperate situation, he injects the serum, awakening supernatural werewolf abilities. The two discover they are both victims of persecution by the Apex Corporation, and thus form an alliance for revenge. They subdue underground gangs, battling the Corporation's forces all the way and breaking through numerous deadly traps. After enduring fierce combat, Leo eventually teams up with Serena, who possesses the Beta serum, to crush Victor's conspiracy, overthrow the Apex Corporation, and upon the ruins of the old empire, establish their new order.
