Fisherman's Hope — David Feintuch

THE SEAFORT SAGA
There is nowhere to hide from the deadly night. Even our human ark, our Earth, is only a fragile raft adrift in the infinite darkness. But with the strength of the blessed, and the courage of the damned, can one hero set humanity's course toward the dawn?

Naval Academy Commandant Nicholas Seafort is a legend to the masses, an idol to his hundreds of teen cadets. They don't see the tormented soul of a man who believes that merciless duty has led him to betray every friend he ever loved, every ideal he ever cherished. After a lifelong ordeal, Seafort needs time. Time to reflect. Time to heal.

Instead he is pulled into a maelstrom of crisis, corruption, and danger as the helpless, unprepared Earth faces annihilation from a horde of alien attackers. Alone at the center of a cosmic apocalypse, Nick Seafort must face his final battle...

And his most unforgivable sin.