Boston beat cop Aspen Wolfe gets the surprise of her life when she learns she's a shapeshifter. Her abilities awaken as a ruthless regime unleashes its troops to eradicate the shapeshifter population.

Forced to run or be hunted, Aspen meets Dr. Tora Madigan--a beautiful and resourceful shapeshifter who oversees an underground sanctuary. Her attraction to Tora is a welcome distraction, but the fierce lioness plays hard to get. Together they discover that Aspen is a powerful shapeshifter thought to be extinct. Her existence gives shapeshifters everywhere a fighting chance. But there's one small problem: she doesn't even know how to shift. With no one else up for the job, Tora agrees to train her.

Aspen soon finds herself leading a group of extraordinary shapeshifters who are willing to risk everything to save their species. When the sanctuary is targeted for annihilation, she must come up with a game plan. Fast.