Twelve-year-old Leon loves video games. When he plays, he feels confident for just a little while. The rest of the time he feels like a loser. So Leon is shocked when Nico, the coolest kid and the son of a video-game developer, invites him over to test out the newest game at his dad's high-tech lab. To play, they must submerge themselves in giant tanks filled with nanobots, which are programmed to interact with the players. It sunds perfectly safe... but is it?