Humankind headed out to the stars not for conquest, nor exploration, nor even for curiosity.
Humans went to the stars in a desperate crusade to save intelligent life wherever they found it.
A wave of death was spreading through the Milky Way galaxy, an expanding sphere of lethal gamma radiation that had erupted from the galaxy’s core twenty-eight thousand years ago and now was approaching Earth’s vicinity at the speed of light. Every world it touched was wiped clean of all life.
Guided by the ancient intelligent machines called the Predecessors, men and women from Earth sought out those precious, rare worlds that harbored intelligent species, determined to protect them from the death wave, to save them from the doom that was hurtling toward them at the speed of light.