Kim Harrison

Against an ancient shadow with a deadly agenda, Petra Grady's luck may be about to run out, in the next book in the enthralling contemporary fantasy series from the author of the #1 New York Times bestselling Hollows novels. It's been months since Petra Grady bonded with the shadow Pluck. With the help of researcher Benedict Strom, she has made a place for herself at St. Unoc University as the first weaver to use shadow magic in a thousand years.
But some are not happy to acknowledge the new shadow/weaver pair, and Petra and Pluck aren't surprised when they're blamed for every recent trouble. When a new weaver is drawn to St. Unoc, Pluck quickly realizes the novice magic user has not come alone. Trailing her is Thoth, a devious shadow responsible for betraying his own kind and setting mage against weaver thousands of years ago. His goal hasn't changed, and when Thoth turns both the mage courts and the university against Petra, she and Pluck must risk everything to uncover a truth that even Pluck has forgotten.
Shadows, though, have earned their terrifying reputation, and if Petra can't prove her and Pluck's innocence and capture Thoth, any hope of balance will be gone-taking Pluck and her with it.