Under My Skin — Charles de Lint

From one of the world's leading fantasists comes an exhilarating new series that will thrill teen and adult readers alike.For the past six months, something has been happening to young people in Santa Feliz. Week after week, there's news of another teen changing shape, transforming from human to wild animal and back again. The federal government has stepped in, running public service announcements calling for affected youth to turn themselves in for “orientation and training.” Josh Saunders has seen the news reports, but he is still unprepared when it happens to him. One minute he's arguing with his mother's boyfriend and the next, he is looming over the man, blood dripping from his claws -- he has transformed into a mountain lion. When he switches back to his human body, he knows his life has changed forever. He has become a Wildling. Trusting only his best friends Des and Marina with his secret, Josh tries to return to regular living. But an encounter with Elzie, another Wildling, brings him unwanted attention from the authorities. And when an accidental betrayal reveals Josh's secret, his carefully constructed cover is ripped apart, forcing his friends to intervene. They must grudgingly put their trust in others, including other Wildlings -- and, most challenging, in each other -- if they ever hope to save him.