Agent Arin: A Man Alone. Epic Literary Universe Series

It's hard to be a Justice Keeper when your worst enemy is your own checkered past. Haunted by the years he spent working for the Overseers, Arin Corali yearns for redemption. But opportunities to prove himself are rare; as a newly-minted Keeper, most of his assignments are tame. That will all change, however, when trouble stirs on the abandoned world of Abraxis. With his crimes exposed to the public, Arin must travel to the ancient stronghold of the Overseers, a world of horrors where human settlements are few and scattered across the vast desert.
He must navigate through a complex web of criminal syndicates, searching for a power that can usurp control of starships and turn them against their own crews. Arin's investigation eventually brings him to the subterranean lair of his former masters. And there, he will confront a darkness unlike any he has ever faced before.