Steven Bishop is extraordinarily ordinary. He goes to school. He rides his motorcycle. He stutters. His best friend is a former Colombian cartel hit man turned cook/construction worker. You know, ordinary. All that changes the day Becky Moore walks into his classroom. Becky is dazzling, enigmatic.

One day Steven gives Becky a ride home on his motorcycle. There, they discover a severed arm, one of the fingers of which still has an unusual ring attached: a circle, in the middle of which is a heart, at the center of which is a bold number 37. While comforting Becky, Steven discovers a tattoo at the base of her neck: it is the same symbol. And so begins a thrilling descent into a world of crime and murder, a ride wilder than any Steven has taken before.