 Though the novels feature similar themes and many of the same characters, they do not take place in strict continuity with each other; for instance, the main character of "Mystery", Tom Pasmore, goes on to appear in "The Throat" and two other novels, but a major element of Tom's backstory- a childhood accident that left him hospitalized and incapacitated for several months- is transplanted to the main character of those novels, a writer and Vietnam veteran named Tim Underhill.A similar accident actually happened to the author himself as a child.The title "Blue Rose" refers to the signature of a serial killer who committed a series of murders in Underhill's hometown (the words Blue Rose were written on walls near the bodies of each victim).