Chasing of the Dark is book three in the Dark Universe setting by Jason Halstead
Aden and Twyf, human and Tassarian lovers, are running for their lives. An entire alien race, the Kesari, are chasing them across the universe with the intent of retrieving the artifacts they stole and insuring the secrets they've learned are never shared.
While they stay one step ahead of the Tassarians, the universe continues to change around them. They've unleashed a long forgotten energy that is disrupting everything, from genetics to the laws of physics. The secrets to the mysterious energy lie in the artifacts they have, and the key to unlocking them may very well be in the Terran Naval station Aden grew up in.
The Kesari won't be denied so easily, however. Aden and his friends have to race against a race with technology so superior it might as well be magic. Magic the Kesari intend to use to one inevitable end: destroy Aden, Twyf, and everyone else that has come in contact with them.
Look for these other Dark Universe stories:
Book 1: Into the Dark
Book 2: Out of the Dark
Book 3: Chasing the Dark