In the real world Leon isn't built to be a hero but he must become one when he gets trapped in a cutting-edge virtual-reality game.

Twelve-year-old Leon loves video games. When he plays he feels confident and amazing for just a little while. The rest of the time he feels like a loser. So Leon is shocked when Nico the coolest kid ever 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 and form the physical gaming world. It sounds perfectly safe. But a glitch causes the tiny robots to start behaving oddly putting the boys in real-life danger. Now it's up to Leon to slay a dragon to beat the game and save Nico and himself...before the timer runs out.