In 1918, a world war raged, and a lethal strain of influenza circled the globe. In the midst of all this death, a bizarre disease appeared in Europe. Eventually known as encephalitis lethargica, or sleeping sickness, it spread worldwide, leaving millions dead or locked in institutions. Then, in 1927, it disappeared as suddenly as it arrived.

Asleep, set in 1920s and '30s New York, follows a group of neurologists through hospitals and asylums as they try to solve this epidemic and treat its victims-who learned the worst fate was not dying of it, but surviving it.