Spots 
Lord Ruthven enters London high society, captivating observers with his cold, distant demeanor and strange gaze. Young Aubrey, fascinated by Ruthven's mysterious aura, joins him on a tour of Europe. In Rome, Aubrey discovers that Ruthven's patronage ruins those who accept it, while his charity only aids the depraved. Horrified by this malice, Aubrey separates from his companion and travels alone to Greece.
In Greece, Aubrey falls in love with Ianthe, a local maiden who warns him about local legends of blood-drinking spirits. While exploring a dark forest during a storm, Aubrey hears horrific screams inside a ruined hovel. He arrives too late to save Ianthe, who lies dead with fatal puncture wounds on her neck. Severely ill with fever, Aubrey is nursed by a surprisingly reappeared Ruthven, and the two reconcile.
Traveling together through rugged terrain, Aubrey and Ruthven are ambushed by bandits, leaving Ruthven mortally wounded. Dying, Ruthven demands Aubrey swear a sacred oath to keep his death and crimes secret for a year and a day. Aubrey swears, but when he returns the next morning to bury the corpse, Ruthven's body has vanished without a trace. Aubrey returns to England shaken and bound to absolute silence.
In London, Aubrey is horrified to find Lord Ruthven alive and courting Aubrey's own sister. Bound by his solemn oath, Aubrey cannot speak out to expose Ruthven's undead identity, suffering a severe mental collapse from the agony of his silence. On the final day of the sworn period, the marriage takes place. As midnight strikes and the oath ends, Aubrey reveals the monster, but rescuers find his sister dead and bled dry.
An aristocratic predator bound by a sacred oath exposes the deadly peril of romantic fascination and gothic horror.