No one knows how it started. Domestic animals began to go wild, reverting to their primal states and lashing out at their owners. Felicia Owens, CDC scientist in Los Angeles, was attacked out of the blue by her cat. Now, Felicia is fighting bouts of irritability, anger, and outright primal rage. When others begin acting in a similar way, Felicia realizes that she needs to figure out what's going on and how to cure it before it's too late. Maybe it already is.