Life after the zombie apocalypse is pretty good for 13-year-old Jack Sullivan: he lives in a cool tree fort with his best friends, speeds through town playing Real-Life Mario Kart, has a crew of monster buddies, battles zombies on a regular basis, and generally treats life like it's a video game! But then Jack's friends make a startling discovery: they may not be the last kids on earth after all.

That's great news for everyone…except Jack. He's sure that once they've found other humans, his friends won't stick around for long. Jack's only hope for keeping things the way they are is to prove that everything here is perfect—that life is crazy fun, and nothing else could possibly be better…ever!

There's only one problem: it's hard convincing his friends that everything is great when they're being hunted by a monstrous Nightmare King and an ancient evil who won't rest until Earth has been devoured. Crud! Who knew life after the monster apocalypse could be so complicated?