In the wake of the Civil War, William Mumler seized America's imagination with his "spirit photographs," images that featured the ghostly presence of a lost loved one alongside the living subject. Mumler was a sensation, and his patrons included Mary Todd Lincoln, who arrived at his studio in disguise. Recounting Mumler's rise and fall, Peter Manseau discusses the photographer's circus-like trial on fraud charges, starring P.T. Barnum for the prosecution. The judge's verdict is rather surprising, and as Manseau details here, the mystery of these photographs went unsolved. Illustrated throughout with Manseau's evocative images, this New York Times Book Review Editors' Choice offers a snapshot of America at a crossroads, in thrall to new technology while clinging desperately to belief.