Her distraught husband was no help. Gibbering uselessly, he couldn’t focus enough to give a coherent history, leading Compton at first to consider the possibility that some environmental problem had affected both spouses. But no: the husband was mentally intact, just wracked with grief. She left the room and went to the doctor’s lounge, where she got a cup of coffee from the machine and a little packet of crackers from the snack drawers. She took them back to Rosita’s room and handed the items to her husband, guiding him gently to a chair. “Here,” she said. “Sit. You must be exhausted.”

Rosita’s husband ate and drank as Compton threw him some softballs, easy stuff about where they lived and the ages of their kids and whether they’d traveled recently. He started to calm down, and she kept her voice reassuring, keeping him talking, before slipping in a few questions about his wife. This time, he’d settled enough to answer.

Rosita had seemed normal until about a week ago, when she began forgetting things. She’d space on the name of their baby or start a task and abandon it midway, without ever realizing she’d been involved in it. A gifted artist, she possessed a roomful of supplies but seemed bewildered one morning by what to do with a can of linseed oil. She placed her purse in the refrigerator and a can of Coke in the baby’s crib. It wasn’t until she’d yanked up her dress and peed in the hallway, however, that her husband became truly alarmed. He wanted to take her to a doctor, but his job didn’t provide insurance, and they were barely eking out enough to pay their bills, so they decided to wait. Then this morning she’d woken up aphasic—no speech whatsoever. On exam, she demonstrated myoclonus—involuntary muscle jerks—and, when Compton tried to get her to walk, ataxia. She could bear weight, but her gait was lilting, wobbly, uncoordinated. There were no focal findings; no localization to one side of the body or the other. Compton suspected a stroke, but where in her brain would a stroke produce this constellation of symptoms? And why? Why would this happen to a twenty-eight-year-old?

The CT scan of the brain showed nothing unusual. Compton performed a lumbar puncture, drawing off spinal fluid for analysis, but the immediate results weren’t consistent with a brain infection, like you might see with encephalitis from bacteria or a mosquito-borne illness, for example. Bloodwork was also normal. They got lucky while waiting for a bed upstairs; an MR scanner was open and could take her right then.

Afterward, waiting for the MRI results, the husband again became tearful and agitated, his head bowed over Rosita’s chest as she stared into space. Compton checked on them when she could, but juggling half a dozen complex other patients made it difficult. She ran through Mrs. Sosa’s labs again, tuning out the sounds of the department: people crying and yelling, the clatter of the printers, the swish of the big automatic doors behind her. Nothing.