The Soldier

"In a far corner of space, on the very borders between humanity's Polity worlds and the kingdom of the vicious crab-like prador, is an immediate threat to all sentient life: an accretion disc, a solar system designed by the long-dead Jain race and swarming with living technology powerful enough to destroy entire civilizations. Neither the Polity nor the prador want the other in full control of the disc, so they've placed an impartial third party in charge of the weapons platform guarding the technology from escaping into the galaxy: Orlandine, a part-human, part-AI haiman. She's assisted by Dragon, a mysterious, spaceship-sized alien entity who has long been suspicious of Jain technology and who suspects the disc is a trap lying in wait."--Publisher's description.