Fall of Man in Wilmslow

Following is the blurb of the eponymous book:

From the author of the #1 best seller The Girl in the Spider's Web--an electrifying thriller that begins with Alan Turing's suicide, and then opens out to take in a young detective's awakening to painful secrets about his own life and the life of his country.

It's 1954. Several English nationals have defected to the USSR, while a witch-hunt for homosexuals rages across Britain. In these circumstances, no one is surprised when a mathematician by the name of Alan Turing is found dead in his home: it is widely assumed that he committed suicide, unable to cope with the humiliation of a criminal conviction for homosexuality. But young detective sergeant Leonard Corell, who had always dreamed of a career in higher mathematics, suspects greater forces are involved. In the face of opposition from his superiors, he begins to assemble the pieces of a puzzle that lead him to one of the most closely guarded secrets of the war: the Bletchley Park operation to crack the [Enigma codes of the Germans].

On the basis of the above blurb, this would appear to be a perfect book for me. Unfortunately I found it very disappointing - maybe because I have read Turing's biography several times, along with several books about the Enigma, and this story had very little new information to impart. As a devastating critique put it (from "Timescape"), there is much in this work which is original and much which is correct. Unfortunately, what is correct is not original, and what is original is not correct. A book with a similar starting point - "Enigma" by Robert Harris - is much better, although the film of the book wasn't that good (as always). 

Several reviews have mentioned that the pace of "Fall of man" is glacial. I think that the pace was not the problem, but rather the character of the protagonist, Leonard Corell, who one minute seems to be very bright and the next very dull. Maybe this was the pace of life in provincial Britain in 1954, still worn out from the war; it is mentioned in the book that food rationing is about to end. There are several mentions of Burgess and Maclean, along with a hint that Turing might have been blackmailed by the Russians because of his homosexuality. I suppose that this supposition is valid, although anyone who had known Turing would have realised how unlikely this would be. In real life, I've never come across such a suggestion. There is also mention of Philby and Venona, which seems an extremely unlikely event for 1954.

The standard of this book is far lower than the three Girl in the ... books that Lagercrantz has written, but then not every book can be a winner.