A book from the Darkest Minds Series, based on a girl who has a power everyone is most afraid of. 

Fractured by an unbearable loss, Ruby and the kids who survived the government's attack on Los Angeles travel north to regroup. With them is a prisoner: Clancy Gray, son of the president, and one of the few people Ruby has encountered with abilities like hers. Only Ruby has any power over him, and just one slip could lead to Clancy wreaking havoc on their minds.