Julia Fawlks wants to help her quirky friend Bea get ahead with her new career in hypnotherapy, so she gives her access to her house on the edge of Windsor Forest with the idea Bea can use one of the rooms to practise from when Julia is at work. What could be the harm in such an arrangement between firm friends? But Julia begins to have vivid dreams of liaisons with a horned man who comes for her. At first they are a pleasant distraction then they become increasingly intrusive, and ever more disturbing. Soon the horned man is no longer a figure in a dream; he is becoming manifest and his amorous attentions are now arbitrary demands on Julia. When Julia tries to expel her ghostly stalker, the horned man becomes increasingly violent and his insidious presence turns to possessive control. And that's when Julia notices the faint trace of a necromancy circle drawn on the patio in her garden. Just what has Bea been doing at her house? Who is the horned man and will Julia be able to shake him off?