In 2157, humanity discovered it was not alone in the universe. Thirty years later, they found a peaceful place among dozens of galactic species. But this idyllic future is overshadowed by a dark past; reapers, a sentient race of machines responsible for cleansing the galaxy of all space-faring life every 50,000 years, are about to return. The leaders of the galaxy are paralyzed by indecision, unable to accept the legend of the reapers as fact. But one soldier has seen the legend come to life. And now, the fate of the galaxy depends on him.