Jenna Paine is a super spy, genetically enhanced to be more than human. Nadia Velasquez is a living weapon of mass destruction. When the secret organization who built them both decides they are no longer useful, two enemies are thrown together for the only purposes they could have in common: survival and revenge. There's only one way out of The Pinnacle, and that's on a coroner's slab. Jenna lives through a treacherous attack vowing to exact her vengeance on the people who trained her to be the most deadly agent on the planet. Wounded and on the run, she turns to the man who's sworn to make her face charges for her involvement in The Pinnacle's nefarious schemes. After years spent hiding from The Pinnacle, Nadia runs into the one thing she never counted on: Shelf life. As her body breaks down, she realizes it's only a matter of the short time she has left to redeem her existence and give her daughter a chance to live free. In the final showdown, the two transhumans join forces against a common enemy, and The Pinnacle come to know the deadly significance of… Critical Mass