Boris Karloff stars in this story of a corrupt government official and the young woman who tries to speak out against the horrors of a London's most notorious insane asylum, St. Mary of Bethlehem--more commonly known as Bedlam. When Nell Bowen (Anna Lee), the mistress of James Sims (Karloff), witnesses the horrors of the mental institution Sims oversees, she tries to speak out to help the inmates. Rather than have his graft and abuses exposed, Sims has Bowen committed as a "willful" woman, obvious proof of her insanity. But the inmates have the last word when they enclose a still-conscious Sims inside a basement wall in this horror classic.