Dr Mercer is assessing two patients, Leo and Maya, who have both been referred to a psychiatric clinic with suspected schizophrenia.

• Leo reports hearing a whispering voice that tells him his neighbours are spying on him, and he has recently started wearing foil under his hat to block their signals.
• Maya has stopped speaking almost entirely, responding only in one-word whispers when prompted, and shows a complete lack of interest in her usual hobbies, sitting staring at the wall for hours.