What is evil? Is it a spiritual force that mortals can confront, but only God can understand? A political reality, as ever present as war, poverty and hunger, that we may work to alleviate, but never fully extinguish? Or a meaningless superstition? It depends on whom you ask. Travel into the trenches where three front-line practitioners confront evil with very different sets of tools, including the Bible, a military convoy and a brain scan. Also examine Philip Zimbardo's landmark Stanford Prison Experiment where the psychology of evil was so vividly brought to life.