Content Warning: The source material features discussions of psychosomatic disorders and trauma.

Anna O tracks the significance of sleep (or lack of sleep) and dreams. This theme is fundamental to the premise, plotline, and mystery. Blake uses sleep as a relatable, vulnerable state that everyone experiences and then amplifies it into a situation of horror: Anna’s alleged murders while sleepwalking. The effects of sleep disorders are heightened to create life-and-death stakes, introduce the question of Anna’s culpability, and offer scientific insight into sleep and dreams. By employing the knowledge of Ben as a sleep expert, Blake uses this theme to ascertain meaning and truth. Countless times, Ben offers insight into sleep with factual evidence, including that people spend 33 years of their lives asleep, that sleep is a second life, that sleepwalkers do complex things like drive, etc. All of Ben’s points complicate the topic of sleep. The whole text tries to answer what sleep, lack of sleep, and dreams convey, and if Anna’s sleepwalking episodes and dreams reveal the objective truth of the murder mystery.

Along with Ben’s expertise on sleep and dreams, Anna defines the importance of sleep and the effects of the lack of it. As a lifelong sleepwalker with frightening episodes, Anna has an unhealthy relationship with sleep that leads to self-imposed insomnia.