During a test, Zara kills eleven guards. Dr. Hazel Zoula compliments her and then shows her another, newer experiment named Viper. The two get acquainted before Colonel Vladimir Dietrik arrives and takes Viper away to be cloned.
The cloning process does not go as planned, and the resulting clone proved malicious and shadowy. It escapes the premises and Dietrik sets off after it, leaving Zoula and Zara to care for Viper.
Zara and Viper head to New York city to locate the corrupt Viper. A fight ensues, but after Zara uses her claws on the clone, it grows similar claws and defeats her, escaping with Viper captive. The two fight briefly but soon Viper is attempting to escape. She is rescued by Dr. Zoula and Zara but the clone captures Zara.
Zara and the clone briefly fight in a desert before returning to Central Park. There Viper rejoins the fight and kills the clone by dropping it from a tall height after the pain grew too great for it to concentrate.
Viper and Zara reunite with Dr. Zoula, and the three affirm their readiness to stop Col. Dietrik once and for all.