Nine years of unexplained nightmares and hallucinations left Pat Long questioning his sanity. Finally the cause was uncovered: a rare tumour the size of a lemon growing in the right side of his brain. Two major surgeries have successfully controlled the cancer. Determined to come to terms with this new reality, Pat sets out to discover the truth about memory, dreams, imagination and consciousness. Here he works with scientists and clinicians whose cutting-edge research is providing new insights into the capabilities and the fragility of the brain, as well as drawing on philosophy, history, literature and his own remarkable experience.