A girl named, Riko and her robot friend, Reg, journey down into a deadly, otherworldly chasm, known as the Abyss, in search of her lost mother.A girl named, Riko and her robot friend, Reg, journey down into a deadly, otherworldly chasm, known as the Abyss, in search of her lost mother.A girl named, Riko and her robot friend, Reg, journey down into a deadly, otherworldly chasm, known as the Abyss, in search of her lost mother.