One of the wonderful things about crime-novels writen more than 20-odd years ago is that they had no DNA-testing back then. Of course it's a great thing for the real world but for crime-stories it means that so many possibilities for great plotlines get ruined. This book is just possible because there is a lot of confusion about the identity of one body. Today it would be much easier to solve that problem (or at least tell that the body was not a certain person which also would helped a lot) but fortunately this book was written at a time where we didn't yet have all this and so we get another highly enjoyable read.
I don't think I can say anything new about this book what I didn't already say in my reviews of the previous Morse-novels. It is again really clever. Colin Dexter is one of the crime-writers who does not think that his readers are all stupid. I've read so many novels where a character mentioned some detail and immediately a warning-light flashed up in my head 'Remember this! It will be important later!' because there were hardly any other details mentioned. Morse-novels are different from this. A lot of details get mentioned and a lot of those will turn out to be not important at all (and with those that are important it is far from clear why they are important).
Dexter is also the only author who can write sentences like 'He did not yet know that he'd never return to Oxford' without annoying me because - like almost everything in a Morse-novel - it can easily be a red herring and not mean what you think it means.
I did feel a bit let-down by this one because I considered a small part of the solution somehow cheating and I missed the Morse-Lewis interaction. It was done so beautifully in the last one but here they barely had any at all.