Seigneur du Temps
As the Fifth Doctor and his companions vacation in Tasmania they become caught up in a scheme by the Time Lord Ruath to resurrect the vampire Yarven (from "Blood Harvest"). Ruath sends a vampire baby to attack the Doctor and turn him into a vampire, but the child instead attacks and converts Nyssa. Unable to provide Yarven with the Doctor's Time Lord blood, Ruath gives her own blood to Yarven, causing her to die and regenerate into a vampire Time Lord.