"Dad. I've got very, very, very bad news. Peter was killed tonight . . ." With that middle-of-the-night phone call, life for the Mayer family plunged from "best-ever year" to months and years of dealing with the oppressive presence of Peter's unending absence. A letter from his father to the freshly deceased Peter, intended for the memorial service, became the first in a torrent of letters from his dad to Peter, though which his dad poured out agonized and angry grief. In the letters, Pete...