How to make friends and then kill them

Left to their own devices by their alcoholic mother, Ada and Sam cultivate an insular world into which they soon draw a third wheel - a pockmarked, limping wallflower named Dorrie. In the years spanning childhood to young adulthood, these three troubled girls learn to lean on each other completely, finding ways to fill each other up and to tear each other down. But when a horrible accident turns their realityupside down, they find they must decide whether they will continue to foster their familiar, codependent cycle, or whether they will break free, with or without each other's aid.