A new doctor at Bethlem Mental Hospital uncovers a bit more than your run-of-the-mill mental disturbances afflicting her young patients at the hospital.

Aside from the tortures applied by demons in human guise, she is apprised of an entirely different world of horrors to which most people, fortunately, are never introduced; else they too should surely go mad.

The good doctor has to learn how to deal with the afflicted children and how to best use the new knowledge she encounters, much to her own horror.