Jasper Flint is in teenage hell. He is thirteen, an only child whose adoptive parents want nothing to do with him, and spends the majority of his time dodging the school bully at West Denver Middle School. In fact, a brilliant purple gemstone found with Jasper when he was anonymously dumped off at an orphanage, a talisman he is relentlessly mocked for, is the only tangible link to a mysterious past. During a school field trip to the Museum, a day seemingly like any other, Jasper’s world as he knows it changes forever. His gemstone unlocks a door to another world, the Underworld, where gemstones equal power and a civilization on the brink of extinction battles to survive against a seemingly unstoppable villain. Jasper soon learns his arrival in the Underworld is no accident and that he represents civilization’s last hope. As Jasper comes to realize that all of the answers surrounding his origins, birth parents and gemstone lie in the Underworld, he must confront self-perceived limitations on what a smallish teenage boy pushed around all his life can accomplish. And while Jasper struggles to find a way home from the Underworld, his two best friends, Tom and Nina, execute a frantic search to find Jasper; a search that puts their own lives in danger and leads to an outcome none of them ever envisioned.