it was in that instant , while staring at his friend , that he felt the pieces suddenly fall into place : the untraceable e-mails ... alvin 's brief infatuation with rachel and his offer to let her visit ... the fact that alvin had made a point of bringing her up in conversation , which meant he was still thinking about her ... rachel 's recent unexplained absence coupled with alvin 's need to hang up the phone because he had company .