Lost Soul is book 5 in the space fantasy series, Voidhawk.
The new Empress of the elves thought the only thing standing in the way of prosperity for the reunited Elven Empire were the scattered elven rebels that clung to their racist ways. Progress seemed slow but certain until an old enemy emerges from the past. Beset by potential foes from every angle and unsure of who they can trust, the crew of the Voidhawk is near the end of their luck. Outnumbered by beings beyond their power, even the greatest sacrifice may not be enough to keep the void safe and return what was lost.
Look for these other Voidhawk books:
Book 1: Voidhawk
Book 2: Voidhawk - The Elder Race
Book 3: Voidhawk - Redemption
Book 4: Voidhawk - The White Lady
Book 5: Voidhawk - Lost Soul
Book 6: Voidhawk - The Edge of Forever
Book 7: Voidhawk - Broken Shards
Book 8: Voidhawk - Fallen Goddess