The detectives investigating the homicide of videogame designer R. H. Lo are challenged to play his latest game in order to find clues to the identity of his murderer—his business partner, Rita Scott. However, Det. Nick Knight is the only one to recognize the challenge for what it really is. His colleagues simply think that he has become obsessed with playing the game. As it is a vampire game, Dr. Lambert, in particular, is very concerned that this means that he is regressing in his search for a cure.