Captives in Obscurity. Sons of the Starfarers, #5

There is no escape beyond Star's End. The deadliest pirates in the galaxy have stolen the technology that will transform it. Now, on the edge of known space, they are poised to start an empire of their own. Isaac and Reva are running out of time. Neither of them knows the extent of Gulchina's plans, or whether the madwoman will keep them both alive after she achieves them. But an unexplored planet beyond the Far Outworlds holds an ancient alien secret that not even Gulchina has uncovered.
That secret will tip the balance inSONS OF THE STARFARERSBOOK V: CAPTIVES IN OBSCURITY