Medicine, in the early 1800s, was a brutal business. Surgery was performed without anaesthesia, while conventional treatment relied on leeches, cupping and toxic potions. Two pioneering men of science aimed to change all this - the progressive physician John Elliotson, and Thomas Wakley, founder of The Lancet magazine. But when the flamboyant Baron Jules Denis Dupotet arrived in London to promote the latest craze that was sweeping through Europe - mesmerism - the scene was set for an explosive confrontation . . .