The author believes that Carter and Carnarvon discovered Tutankhamun's tomb several years earlier than they claimed. Using secret access from other tombs in the immediate area they systematically stripped the tomb of much of its treasure (60% it is claimed), leaving only enough to guarantee them glory and fame once their discovery was announced. In the process they changed the layout and size of the tomb, sealing off the rooms they had emptied and building false walls to hide their activities. It would have been helpful to have had a floor plan of the "original" tomb to understand how it had been changed and how it related to the other tombs through which Carter and Carnarvon are supposed to have gained access.
Many of the author's claims are fascinating and feasible, though there is precious little evidence or proof.
Mr O'Farrell claims on several occasions that anomalies in the tomb are the result of Carter and Carnarvon's clandestine activities, rather than haste and carelessness on the part of the original burial party. More than once he questions whether pious priests would be so careless, as for instance in the case of the wrong orientation of the shrines surrounding the sarcophagus. Several other authors have attributed such mistakes to the political and religious climate at the time of Tutankhamun's death. One of his immediate predecessors was the so-called heretic king, Tutanhkamun had elected or been forced to restore the "old" religion, and some believe he was murdered - are these not grounds to explain why his burial was undertaken in haste?
The whereabouts of the stolen treasure is not accounted for. It was supposedly sold to private individuals and museums, though presumably not attributed to Tutankhamun's treasure. It is hard to imagine how so many priceless items could have vanished into collections around the world without someone somewhere making a connection with the tomb.
Much is made of British and American dominance of archaeology at the time, and the arrogance that went with it. This was undoubtedly distasteful, particularly the flouting of regulations established by the Egyptian authorities. It is hard, however, to accept the author's assertions that both Carter and Carnarvon were vainglorious and greedy egomaniacs.
There ARE unanswered questions which put Carter and Carnarvon under suspicion (eg the uncatalogued lotus head of the boy king found in a wine crate in Carter's laboratory) but this book does not prove the theories it puts forward. Those theories are however a very good read, and might hopefully form the basis for further investigation.
There are however several subsequent chapters which are a challenge to even the most open-minded reader. Describing the opening of the sarcophagus and the interlocking coffins, the author asserts that in all likelihood the tomb was not that of Tutankhamun but of his brother Smenkhare (p150). In a later chapter papyri allegedly found in the kilts of the two sentinel statues were rapidly suppressed by Carter and Carnarvon because the pharaonic family history related in them identified Akhenaten as Moses and Tutankhamun as Jesus. "The establishment" then went on a killing spree under the guise of the mummy's curse to silence anyone with knowledge of the papyri or their contents.
In summary, the earlier chapters covering the alleged deception by Carter and Carnarvon certainly give found for thought. However, in my view, the later portion of the book should have been published separately. The theories about Akhenaten being Moses and Tutankhamun being the Messiah belong elsewhere. I am not sure where to put the idea that Sigmund Freud was murdered for believing in such theories.