Dark Pilgrim Rising: Book one of the Dark Pilgrim Series. Dark Pilgrim Series, #1

The Emperor of the Imperium has been assassinated. The Lord Marshall Bhagavan, military leader of the Imperium, strives to keep the Greater Noble Houses from tearing apart the Imperium in their bid to claim the vacant throne. The Church of the Blessed Prophets, eager to regain their ascendency over humanity, see the vacant throne as the perfect way to acheive their goals. Alien species that have been kept suppressed by the Imperium see a chance to free themselves.
Enter Ailanthus and Tethys, friends all their lives and it has been that friendship that has helped them survive the twenty years imprisonment in the infamous penal colony of K'ar Krack'a. Now that their one chance to escape has come, they question the coming together of far too coincidental events and struggle to make sense out of a world that seems to be falling apart around them. Thus starts books one of the Dark Pilgrim Series, an epic tale of friendship and loss, greed and avarice, and hope.