The story concerns Jander Sunstar, an elfvampire who, despite his affliction, attempts to remain as good as possible. On a trip to Waterdeep to drink the blood of patients of a mental hospital there, Jander falls in love with an inmate who introduces herself as Anna. For about one hundred years the immortal vampire visits Anna regularly, and Anna seems to be similarly ageless. Anna begins to become ill, and Jander, afraid of losing her, tries to turn her into a vampire. Anna refuses. In her last moments of life, when Jander asks her what ruined her mind, she answers "Barovia."
In a rage, Jander kills every last occupant of the asylum, and is transported to the Demiplane of Dread. There, he has his fortune told by a Vistani gypsy before befriending Count Strahd Von Zarovich. The predictions made by the fortune-teller all prove to be true later in the book, sometimes in multiple ways. After a very long period of time spent in Barovia, Jander discovers that the woman he knew as Anna was in truth Tatyana, wife of Strahd's Brother, Sergei, and the woman who drove Strahd to murder his own family. She escaped the castle as it entered the demiplane, but lost her mind in the process. Shocked, Jander bands together with a local cleric and a young thief, to the end of killing Strahd. They fail, though the severe damage they inflict on him forces him to into an extended healing cycle thereby limiting the speed with which he increased in power as a spell-caster. To that end, Jander somewhat succeeded, at least for the time being, and more so prevented Strahd further access to any more of his own knowledge when he walks into the sunlight for his final death.