It began when explorers on the Moon found a space suit containing a human skeleton older than the human race. Then a starship manned by the giant humanoids of Thuria arrived, bringing both the answer to mankind's origins, and also great danger, as Earth was now caught in a struggle between the giants benevolent empire and another offshoot of the human race who regarded the Earth as rightfully theirs. Earth thought they had won the battle, and the future now looked bright, as trade and knowledge flowed back and forth between Earth and Thuria. Then Dr. Victor Hunt received a phone call - and the face - in the phone's video screen was another version of himself, calling from a parallel world. That was the first step in bridging the gap between the parallel universes of the multiverse. Unfortunately, it also meant that enemies who had been decisively defeated in one universe were still alive and dangerous in another, and could arrive in force at any time. And the possibility soon became a frightening reality...