Book excerpt: One day Colin Grant's teenage brother Christopher failed to emerge from the bathroom. His family broke down the door to find him unconscious on the floor. None of their lives were ever the same again. Christopher was diagnosed with epilepsy. A Smell of Burning tells the remarkable story of this strange and misunderstood disorder. How certain people, at a particular moment in their life, start to suffer seizures, often preceded by an aura, of which a smell of burning is one of the most common. For many years epilepsy was associated with mental illness or even possession by devils. People with epilepsy were forbidden to marry or have children. Many became victims of Nazi eugenics programmes. To this day many people with epilepsy - sixty million worldwide - still live in fear of exposure. Grant's book traces the history of the condition and the pioneering doctors whose extraordinary breakthroughs finally helped gain an understanding of how the brain works. He tells the stories of famous people with epilepsy like Julius Caesar, Joan of Arc, Fyodor Dostoevsky and Vincent Van Gogh, and through the tragic tale of his brother, he considers the effect of epilepsy on his own life.