"Jack Harmon can't think of anything worse than getting picked on by bullies at school, until he discovers an even bigger threat. When he finds a cell phone on the bus home, Jack hears a strange voice on the other end. Whoever it is wants Jack to do things--bad things. Jack keeps trying to make his new 'friend' happy. But everyone thinks Jack has lost his mind. How can he overcome something that he can't see but is everywhere?"--from back cover.