So why is he adamant that he will not lead the re-investigation, despite the entreaties of Chief Superintendent Strange and the dark hints of some new evidence? And why, if he refuses to take on the case officially, does he seem to be carrying out his own private enquiries?

For Sergeant Lewis, this is yet another example of the unsettling behaviour his chief has been displaying of late - as if the sergeant didn't have enough to worry about with Morse's increasingly fragile health.

But when Lewis learns that Morse was once friendly with Yvonne Harrison, he begins to suspect that the man who has earned his admiration over so many years knows more about her death than anyone else.