Soon, however, a new and sinister force begins to stir on the island, seemingly disturbed by the very presence of the American fighting forces. Several men disappear under mysterious circumstances, but their bodies turn up horribly mutilated. The sound of drums begins pounding out of the jungle. And Lieutenant Commander McLachlan witnesses a gigantic, half-invisible shape moving atop the mountain at the center of the island.
Soon, the Blue Devils are forced to fight on two fronts: against the known enemy, the Japanese, and an unknown, predatory force on the island that threatens to destroy McLachlan and his men.