02 - Greylorn by Keith Laumer

In a race against time, Earth faces annihilation from a relentless alien plague. The planets last hope lies in the fabled Omega Colony, hidden somewhere in the cosmos. As Lieutenant Commander Greylorn leads the mission to uncover Omegas location, every choice he makes could determine the fate of humanity during its first encounter with an alien civilization. Will he rise to the challenge, or will the weight of the universe be too much to bear? (Summary by Mark Nelson)