Buried and Forgotten - Atlus Frost Adventures, #1

Humans had conquered the solar system and were now ready to explore the wider galaxy. But the galaxy came for them first. Without warning or mercy, an alien armada swept through the Sol system, destroying everything in sight and killing billions. Then, just as quickly as they arrived, they were gone, leaving the human race barely clinging to life. After centuries spent rebuilding their shattered civilization, humans have reclaimed their place among the stars.
And now Atlus Frost is determined to reclaim humanity's lost history. The Moon has silently been keeping secrets. A long-forgotten facility may hold the key to humanity's forgotten past. But from the start, nothing goes as planned, and Atlus may be in over his head as the bodies pile up. He is on the trail of a discovery that will rewrite history if he can piece it together. But some wish for the past to remain buried, and Atlus along with it if he's not careful.