Susan and her friends must prepare for their most important battle with the vampire Richelieu, but they find themselves divided. Wendy has been kidnapped by a centuries-old enemy of her ancestor, Carissa. While they search frantically to save her, a greater danger threatens as Richelieu's army of vampires and humans fills the crevices of Europe. Susan learns the rest of the ill-fated romance between Carissa and the formidable vampire Gabriel of centuries ago and soon realizes that history is repeating. But it is the secret of the cross that might save them all if she can discover it in time.