Giant, solo, 17-year investigation into a man allegedly hired to kill Lee Harvey Oswald and prevent the assassination of JFK. This ten-pound plate of assassination spaghetti and supposition has much to recommend it, including immense research and documentation, and may bear on any final understanding about the apparent plot to kill Kennedy. Russell shows how several schemes gathered steam and then fell through before the final plot succeeded. The thrust of Russell's book is that a double agent for the CIA and the KGB, Richard Case Nagell--who is still alive and has contributed quite a bit to the present work--not only knew Oswald before the killing and was privy to information about several plots to kill the President, but was also part of several espionage dramas played out during the summer of 1963. While under the belief that he was working for the CIA in gathering information about five different groups that were creating the climate for the assassination, Nagell discovered that his real sponsor was the KGB- -and that he was being set up to kill Oswald in Mexico City and derail the JFK assassination. Nagell allegedly has a tape recording (made secretly by himself) of Oswald and fellow conspirators making plans, while Russell says that he has eye-witness proof that the murder rifle was found on the fourth floor of the Texas School Book Depository, then moved to the sixth; and he claims that oil billionaire H.L. Hunt bought the Zapruder film before Time-Life got its duplicate--which Time-Life thought was the original. Deep wading, with a 15-page ``Cast of Characters'' to keep straight.