Ten years ago, "The Great Crumble" wreaked havoc on the world and led to the mysterious emergence of hybrids — babies born part human, part animal. After a decade of living safely in his secluded forest home, a sheltered hybrid deer-boy named Gus unexpectedly befriends a wandering loner named Jepperd. Together they set out on an extraordinary adventure across what's left of America in search of answers — about Gus's origins, Jepperd's past, and the true meaning of home.