![](https://www.skeptic.com/wordpress/wp-content/uploads/Ben-Alderson-Day-340-2x.jpg)
Shermer and Alderson-Day discuss the psychologist’s journey to understand the phenomenon of sensed-presence: the disturbing feeling that someone or something is there when we are alone. Using contemporary psychology, psychiatry, neuroscience, and philosophy, Alderson-Day attempts to understand how this experience is possible. Is it a hallucination, a change in the brain, or something else? The journey to understand takes us to meet explorers, mediums, and robots, and step through real, imagined, and virtual worlds.