«Young Blood» by Brian Stableford

A vampire who calls himself Maldureve comes out of the shadowy borderlands of existence in response to the unvoiced desires of philosophy student Anne Charet. By choosing to see him she gives him substance; after feeding him, she too begins to hunger for blood. Maldureve becomes Anne's lover and mentor but he cannot protect her against his own enemies, mysterious creatures of light who call themselves owls because they believe that theirs is the highest wisdom of all. Anne's boyfriend, psychologist Gil Molari, worries about her health and state of mind, although he knows nothing about his supernatural rival. His anxiety is magnified when he becomes convinced that one of the mind-altering viruses with which he works has escaped from the laboratory. Gil refuses to believe in Maldureve but his refusal to believe cannot save him from becoming the victim of a fierce hunger that he cannot satisfy, which drives him in the end to an unendurable extreme. Anne believes that her experiences are entirely real; Gil believes that his are the products of an infectious madness. Whichever of them is right, they are both in deadly danger, and so is everyone around them. Once they have started on their strange journey, there is no way back. But what can possibly lie ahead of them, when death itself no longer seems to be an end?