My nephew, David Barry, is only eight years old, but I already know how he will die. It will start suddenly. His arms and legs will jerk outward; in lighter moments, his parents call this pose his “Superman.” His mother—my older sister, Tami—will look at her black and silver Timex Ironman watch. She’s never without it. Tami times every seizure because she never knows if it will last a few seconds or a few minutes. It’s the long ones she worries about.