What would you do if you found yourself locked in an underground lab with a murderous alien hunting you? Melissa Allen and her new friends know exactly how it feels.Melissa Allen is summoned to a laboratory where she discovers she's not the only one who saved the world four months ago. There are four other teens who were involved in the mystery of the alien menace. Now, all five of them are to be mentally and physically tested in the lab.Suddenly the lab goes into lockdown, trapping a skeleton crew of scientists and the teens—along with an escaped alien intent on killing them all. With no help from the outside and time running out, it's up to Melissa to keep herself and the other teens safe. How can she do that when she's not sure who she can trust?Someone in the lab helped the alien escape. Someone human.