Leo and Ethan escape with the alien flightsuit that crashed in the Appalachian Mountains. They are pursued by government agents and by the flightsuit's original pilot, now hiding in the mind of the agent who let them escape. Leo discovers the flightsuit's most powerful weapon is the Artificial Intelligence, which he calls "Brother". Brother teaches Leo to use the flightsuit, introduces him to the other "Known" species and compiles an archive of Earth history for delivery to the Explorer home world. Leo wants to take the flightsuit into space, but he's caught between Brother and Ethan, who doesn't trust the alien AI. As the government closes in, Ethan returns to Bumpas Cove, hoping to extract Leo's mother from the NSA's trap. In the flightsuit, Leo travels across country to Area 51, where the flightpack that will enable a return to space is hidden. He must fight his way to the flightpack and survive overwhelming odds in an epic battle inside the most secret place on Earth.