The explorer craft USS Palomino is returning to Earth after a fruitless 18-month search for extra-terrestrial life when the crew comes upon a supposedly lost ship, the USS Cygnus, hovering near a black hole. The ship is controlled by Dr. Hans Reinhardt and his monstrous robot companion, but the initial wonderment and awe the Palomino crew feel for the ship and its resistance to the power of the black hole turn to horror as they uncover Reinhardt's plans.