For 13-year-old Jack, things are going from bad to worse to horrible. First, his parents go missing and he is forced to move across the country, away from everything and everyone he knows. And then he falls through a crack in the earth and into an alien world full of Inner Terrestrials, or ITs for short.

Stuck below ground and imprisoned, Jack is schooled about the ITs. He learns about their history, their real name (the Bennots), their former planet (Helios V), and their mortal enemy, the Malzoyans. The Bennots keep him alive, but he’s got to be watched. And who’s going to watch him? A human girl, Jen, brought down to the IT world as a toddler.

Finally allowed out to see the Bennot world, Jack discovers things that don’t seem possible underground: huge clear lakes, giant factories, green farms, sunlit skies, and a bustling city, along with unbelievable dangers. And, as it turns out, a hidden cyborg army called the Gireens, copies of Earth’s fiercest soldiers from the ages. The only problem is, they have never been tested.

But now, the evil Malzoyans have found the Bennots, and, speeding toward Earth from the dying Helios V, they intend to exterminate all who remain—along with everyone else on the planet. Can Jack and Jen unlock the cyborg army and save themselves, the Bennots…and humanity…from extinction?