 SPOILER: "Eve Channing" is a combination of "Eve Harrington" and  "Margot Channing", the two main characters in  Joseph L. Mankiewicz (qv)s _All About Eve (1950)_ (qv). "Higgs"  is the name of the dead body in Tom Stoppards play "The Real  Inspector Hound", a parody of Agatha Christie