Harvested to near extinction by a race of vicious, insect-like aliens for over a century, a small group of scientists aboard the space station OMEGA feverishly work on the last, desperate plan to save Earth. The result is Alpha Command, a prototype time machine that is nearing completion. It can be used to travel back into Earth's past and stop the alien predators from destroying the human race, and changing the course of history. Adam Drake is the man chosen to take the trip. A genetically enhanced soldier, the fate of the Earth and its human inhabitants rests in his hands. But, before preparations can be completed, every alarm aboard the station OMEGA goes off...