On a Friday afternoon last May, late in the second round of the PGA Tour stop in Fort Worth, Grayson Murray pocketed his ball and told officials he felt unwell. He withdrew from the competition, cleared out his locker, and aimed his courtesy vehicle toward the airport. Few spectators noticed. Murray was thirty years old and had won twice on the tour, which is two more times than most professional golfers ever win, but he was not the kind of incandescent star who drew massive galleries and heavy media attention. He had two holes left to play when he hit the last shot of his life.The next day, word filtered through the old, pecan-lined fairways of Colonial Country Club that Murray had flown to Florida,…