Explore the biological and psychological factors that influence how we experience pain and how our nervous system reactions to harmful stimuli. — In 1995, the British Medical Journal published a report about a builder who accidentally jumped onto a nail, which pierced straight through his steel-toed boot. He was in such agonizing pain that any movement was unbearable. But when the doctors took off his boot, they discovered that the nail had never touched his foot at all. What’s going on? Joshua W. Pate investigates the experience of pain.