At the bottom of everything, by Ben Dolnick

Adam and Thomas become best friends when they are twelve and Adam begins to attend the same prep school. Thomas is “the smartest boy” in Adam’s new school, but obviously not without social handicaps.  Thomas has never really had friends but his oddness is part of the draw for Adam.  They spend afternoons together after school, have sleepovers, and Adam frequently has dinner with them, where he enjoys the stimulating intellectual company of Thomas’s parents.  His own more conventional mother and clueless stepfather are far less interesting.  When they are fifteen, the “incident” occurs that will change both of their lives forever.  Ten years later, Thomas has disappeared into a foreign country and his frantic parents beg Adam to rekindle his long-lost relationship with their son and bring him home.  Adam, himself floundering in adulthood, reluctantly agrees.  The first half of the book is delineates the special friendship of these two boys with sensitivity and insight, but the last half, the rescue, was less believable.  240 pp.