"If you don't follow your heart, you're never gonna know where it went to."Mary Blake, 17, is a deeply religious smartass growing up in the strange little town of Methuen. Her life is already confusing enough, when a murder thrusts her into an underground odyssey in the bowels of the estate where her high school sits.She's learning the various meanings of sisterhood.Her heart is on fire with love.And she holds the keys to all the doors.