City of Night — Michelle West

The House War is the story of the battle for control of the most powerful of the ruling Houses in the Essalieyan Empire -- House Terafin. But it is also the tale of Jewel Markess. Rescued from her precarious existence as an orphan in the slums of the capital city of Averalaan by Rath -- who abandoned his own family when his sister joined House Terafin -- Jewel is gathering together children less fortunate than herself, creating her own den.

But now times are truly desperate within Averalaan's hundred holdings. Street children are disappearing, theft and violence are increasing, and even Jewel's den is finding it hard to make ends meet.

They've been living on their own for some time, but Rath is still their mentor and continues to sell the items they find in the ancient undercity hidden beneath the streets of Averalaan. Then suddenly he orders them to avoid the undercity.

Yet Rath himself refuses to heed the warnings of Jewel's seer dreams. Instead, he allies with the mages of the Order of Knowledge in a secret war against demonic foes, knowing he'll be targeted for death -- or worse. In a last attempt to protect Jewel and her den-kin, he provides a note of introduction to the head of House Terafin -- the sister he'd sworn never to contact.

For only within the well-guarded Terafin manse will the den stand any chance of escaping the unnatural forces reaching out to claim them....