“I’m close to my mother’s heart and know its rhythms and sudden turns. And now! It accelerates at her husband’s voice, and there’s an added sound, a disturbance in the chambers, like the distant rattling of maracas, or gravel shuffled softly in a tin. From down here I’d say it’s a semilunar valve whose cusps are snapping to hard and sticking. Or it could be her teeth.”