Aubrey, a young Englishman, meets Lord Ruthven, a man of mysterious origins who has entered London society. Aubrey accompanies Ruthven to Rome, but leaves him after Ruthven seduces the daughter of a mutual acquaintance. Aubrey travels to Greece, where he becomes attracted to Ianthe, an innkeeper's daughter. Ianthe tells Aubrey about the legends of the vampire. Ruthven arrives at the scene and shortly thereafter Ianthe is killed by a vampire. Aubrey does not connect Ruthven with the murder and rejoins him in his travels. The pair is attacked by bandits and Ruthven is mortally wounded. Before he dies, Ruthven makes Aubrey swear an oath that he will not mention his death or anything else he knows about Ruthven for a year and a day. Looking back, Aubrey realizes that everyone whom Ruthven met ended up suffering.