With middle school starting, Lam Đặng is officially ready for a change. He loves to play Minecraft, embarking on epic builds with his crew--Jazz, Elias, and Britt--in their beloved shared world, the Kingdom of the Killer Bunnies. But Lam also wants to try new things and meet new people. So maybe going into sixth grade with a little distance from his old friends wouldn't be such a bad thing. . . .

Lam's plans change, though, when mysterious letters show up in the gang's lockers. Someone calling themselves The Griefer is threatening to destroy everything the Killer Bunnies worked so hard to build in the Overworld, from their magnificent castle to the surrounding village. If they don't play The Griefer's twisted game, everything will be lost. Lam may be ready for something new, but he's not prepared to give up the old just yet.

Following clues in both the real world and the Overworld, Lam and his friends race to beat The Griefer and save their kingdom, all while trying to puzzle out the identity of their new enemy. Who could do this to them? And, more important, can The Griefer be stopped before it's too late?