An uneasy alliance forms over plans to free Gus and the other kids from captivity. Desperate for a breakthrough, Dr. Singh conducts a risky experiment.

After an eventful, obstacle-strewn journey to find a safe haven, Gus learns more about his origins and how far Birdie was willing to go to protect him.

As Gus learns more about a threat and their dangerous plans, the group races to catch a departing boat. Jepperd and Becky face an impossible decision.