‍On a Saturday night in autumn, an ambulance slid out of a large hospital’s emergency cul-de-sac and silently hit the road. Three of us sat facing each other in the back.Dr. Johanna Lee,1 in red ear warmers and a waterproof jacket, looked like she was going skiing. “Trudy,” she was saying. “Long time no see! What’s it been, two weeks?” Trudy, a sturdy middle-aged woman with big, no-nonsense blue eyes in sweatpants and an old fleece, was dressed as if she were running out to get the mail. But we ...