This Way Up

What is it like to have power over life and death, and yet to struggle with your own humanity? Dr. Henry Marsh is one of England's foremost brain surgeons, a pioneer in his field and respected throughout the world. Surprisingly modest despite all his achievements, he still rides an old bicycle to work and worries constantly about his patients and the potential damage of such delicate surgery. "When push comes to shove we can afford to lose an arm or a leg, but . . . if something goes wrong [in brain surgery] I can destroy that person's character — forever," he says.