The eminent Sir Lockwood Hamilton, a Member of Parlaiment, is murdered and his body is found on Westminster Bridge. Inspector Thomas Pitt and his wife Charlotte are just beginning to investigate when yet another member of Parlaiment is murdered and discovered on the same bridge. The Pitts find one connection between the men--they both voted against female suffrage. Before another politician is killed, the Pitts must find the murderer among an assortment of angry suffragates, anarchists, and scoundrels.