Evolution

"Kai and Shay have gone their separate ways. As both teens continue to search for Kai's sister, Callie, Shay ends up at the Multiverse compound, a scientific cult in a remote area of Scotland. There Shay investigates the origins of the epidemic and a possible cure. And she discovers that her father, Dr. Alex Cross, has plans that jeopardize the lives of everyone in the community. Meanwhile, Kai helps his friend Freja evade capture--but he doesn't realize Freja failed to deliver Shay's last message. It's only when Kai resolves to make his stepfather, Dr. Cross, answer for unleashing the epidemic and murdering millions that Kai begins to make his way back to Shay. And to a chilling, final showdown."--Back cover.