 In nineteenth century middle-Europe, orphaned teenage twins Maria and Frieda go to live with their uncle Gustav Weil, who heads the Brotherhood, a vigilante group trying to stamp out vampirism. But their methods are random and misplaced and the only result is a terrorised populace. The real threat lies with Count Karnstein, and although the twins seem outwardly to be identical, Frieda finds herself much more drawn than her sister to the Count s castle dominating the skyline.