City of Ruins — Kristine Kathryn Rusch

Boss, a loner, loved to dive derelict spacecraft adrift in the blackness of space...

But one day, she found a ship that would change everything -- an ancient Dignity Vessel -- and aboard the ship, the mysterious and dangerous Stealth Tech. Now, years after discovering that first ship, Boss has put together a large company that finds Dignity Vessels and finds "loose" stealth technology.

Following a hunch, Boss and her team come to investigate the city of Vaycehn, where fourteen archeologists have died exploring the endless caves below the city. Mysterious "death holes" explode into the city itself for no apparent reason, and Boss believes stealth tech is involved. As Boss searches for the answer to the mystery of the death holes, she will uncover the answer to her Dignity Vessel quest as well -- and one more thing, something so important that it will change her life -- and the universe -- forever.