The Battle of Zombie Hill (Defenders of the Overworld Series #1)

Rob is on his way home from vacation when his plane goes down over the ocean biome. He eventually reaches shore, but where is he? And what new dangers lie ahead? His attempts at survival barely keep him alive until he allies with Frida, the sole inhabitant of a lonely stretch of beach. Rob learns enough from Frida to survive, but he misses life on his family's horse ranch. Determined to find his way home, he sets off to cross the Extreme Hills—and steps into the middle of an ongoing war. Th...