The Eye, an intelligence agent, shadows the same woman, Joanna Eris (who happens to be a serial killer of men), all over the U.S. for more than ten years, without her ever knowing. The Eye, having been through a messy divorce, hallucinates constantly that his lost daughter is with him, and comes to see Eris as a daughter-substitute–or at least a lost child–leading him to act as her guardian angel.
Marc Behm's novel had previously served as the inspiration for 1983 French film Deadly Circuit (Mortelle Randonnée), directed by Claude Miller.