It is bad luck for Denis Smyth that his book has been partly scooped by the journalist and historian Ben Macintyre, whose Operation Mincemeat came out earlier this year, based primarily on the private papers of Lieutenant-Commander Ewen Montagu, which were unavailable to Smyth. Yet Smyth has all the advantages that accrue to a scholar who has tried properly to master his subject, and he scores over Macintyre on one important point: he has done a lot of work on the archives of the Special Operations Executive, now available at Kew, and has brought to light more than was previously known about ‘Animals’, the deception operation carried out in Greece in parallel with ‘Mincemeat’ at the other end of the Mediterranean in 1943.

He begins by setting out briefly and clearly what the deception service was, and how much it depended on ultra secret information – that is, on decipher, organised from Bletchley Park under the wing of MI6. With decipher’s help, then a deadly secret, the equally secret deceivers could