A woman habitually self-harms, eating light bulbs, a box of nails, zips, and a steak knife. A new mother is admitted with incessant visions of hurting her child. A recent university graduate, dressed in a tunic and declaring that love emanates from everything around him, is brought to A&E by his alarmed girlfriend. These are among the patients new consultant physician Christine Montross meets during rounds at her hospital’s locked inpatient ward as she struggles to understand the mysteries of the mind, most especially when the tools of modern medicine are failing us.