Legendary filmmaker Werner Herzog delves into the mysteries of the brain (artificial or otherwise). Do we really have autonomy over our thoughts? Do we live in a shared fantasy? Is telepathy possible? Can fish dream? Do mice question their reality? How can Siri detect the difference between "knight" and "night"? A fascinating look at the brain's immense capacity, the potential of neurotechnology and its ethical implications. At age 80, Herzog adds a new chapter to his varied and idiosyncratic oeuvre with a fascinating journey through the research, insights and predictions of some of the world's most influential scientists and innovators.