The Eighth Deadly Sin — John Richardson

An attractive English professor finds her 15 year marriage to a homicide cop falling apart. she has lived in the fantasy words of English Literature for as long as she can remember, often picturing herself as Lady Guinevere, queen to King Arthur and living in the mythical kingdom of Camelot. Despite this, she instinctively feels that below the surface lies something so evil that to face it might mean her death; so she remains safe in her world of fantasy. Then one day she is contacted on the internet by a person named Cameo and her life changes forever. She can no longer hide in the fantasy world.