My mother and I are working our way down to Moab, where I will be leaving her in the care of my brother. A road trip with her is a risky thing; in motion, she can become as unmoored as any poor creature in the universe, and as desperate. Thus, I have put Bach’s St. Matthew’s Passion in the tape deck, thinking it will sooth her and, if our luck holds, buy us a hundred or so miles of calm. It’s worked. For a long time we have been mostly silent, caught in a spell of organ and strings.