Rachael Penrose is confined to Bedlam insane asylum in London after discovering that her uncle Victor plans to kill her brother in order to inherit the family fortune. Victor, with a gang of criminals, uses French privateer Sebastien Falconer as the scapegoat for his crimes. When Victor spreads the lie that Rachael informed on Falconer's smuggling activities, Falconer vows revenge on the girl. Gripping suspense and romance play out in front of numerous historical details, including a violent storm that devastated England in 1703 and swept the Eddystone Lighthouse into the sea.