Gregor and the Scars of the Past

It's been three years, seven months, and twelve days since Gregor the Overlander left the Underland for the final time. Now living on the old family farm in Virginia with his mother and two younger sisters, sixteen -year-old Gregor lives as normal a life as he possibly can. He's the up-and-coming star of the track team, gets near perfect grades in school, and has close friends in his teammate Brandon, his cousin Anna, and Anna's best friend Courtney. Although slightly unsatisfied at times, he is finally, truly happy.
But when his youngest sister gets stuck in a bind she can't escape, Gregor is forced to revisit memories of the past and return to the place his family has been avoiding at all costs. But will being the Warrior protect those he loves, or will it be what ultimately dooms them all?