Then she got a call from the neuroradiologist.

“Interesting scan, Dr. Compton,” he said. She didn’t know this guy, but his voice, both condescending and squeaky, set her teeth on edge. “We’re looking at diffuse patchy T2 weighted and FLAIR signal abnormalities, seen throughout the cortex and subcortical white matter, the basal ganglia and the thalami, but there are some additional oddities.”

“What the fuck,” mouthed Compton. Did he think that sentence was comprehensible?

“I’ll send the full report shortly,” he said. “What’s the clinical picture?”

“Rapidly progressive dementia in a healthy twenty-eight-year-old. Some difficulty walking.”

He whistled through his teeth. “It fits. Hmm, let’s see. The cerebellum looks robust, actually. Not sure what to make of that. On another note, you might consider FDG PET imaging to help differentiate limbic encephalitis, which can have FDG avidity in the mesial temporal lobes.”

“Pretend,” suggested Compton, “that I don’t speak radiologist.”

“I’m sorry,” he squeaked, and suddenly she felt guilty for judging him. Perhaps he was a nerd, not a jerk. “I guess I geeked out a little. It’s an unusual scan, especially in this age group. There’s some diffuse inflammatory process going on here. I’d be very worried.”

“I’ll pass that on to the admitting doc, but what are you thinking? This isn’t a stroke, then.”

“Nope,” he said. “It’s odd, almost like what you’d see in certain kinds of autoimmune encephalitis.” He hesitated. “But there are some unusual findings here. The gradient echo sequence shows extensive tiny punctate hemorrhages, which you don’t usually find in an AE. The pattern doesn’t fit perfectly with any described entity I can think of.”

“Thank you,” she told him. She hung up, baffled. What in the world could have caused her patient’s brain to fail so quickly?

This was a once-in-a-lifetime case. But then, extraordinarily, the very next day she encountered it again, this time in a forty-one-year-old man, a lawyer at one of the big firms in Midtown. He’d been fine until a couple of weeks ago, at which point he too had started doing odd things: calling random people from his contacts list and asking them long, nonsensical questions; getting stuck on an elevator because he couldn’t remember how to get to his floor; showing up at an old boyfriend’s apartment in Brooklyn, convinced he still lived there. His husband, bewildered and distressed, had brought him to the ER when he too had lost the ability to speak. By the time he hit the emergency department, he’d been seizing nonstop. His scan, while not exactly the same as Rosita Sosa’s, shared enough similarities that it provoked a tingle of fear. This could not be a coincidence.

Now, at home, Compton set a reminder to herself to follow up with the neurologists caring for these patients to see if any diagnosis had been made or any commonalities identified. In the meantime, she needed something to displace from her mind the image of the vacant faces of her patients.