If it hadn’t been for the postcards, he himself might have succeeded in forgetting by now. Apart from that time some Communist journalist had come around asking about Leonardo under the pretext of wanting to buy a book. But Gabriele had got rid of him in short order.

The series of postcards had begun the year after Gabriele had resigned his commission. Since then, they had arrived annually wherever he happened to be living at the time, all sent from Rome and postmarked on the anniversary of the day Leonardo had died. Since 1993, they had arrived at the shop. They were always the same, a cheap tourist postcard of the Loggia dei Lanzi in Florence showing Cellini’s bronze statue of Perseus holding the severed head of Medusa. Gabriele’s name and address were printed on the right-hand side of the reverse. The space intended for the message had been left blank.

‘We’d better get going,’ said one of the men at the bar. ‘They’ll be waiting for us.’

And they would be waiting for him, thought Gabriele. If not today, then tomorrow. If not at work, then at home. What made it worse was that he had no idea who ‘they’ were. Medusa was something he had put behind him long ago. He had even had the tattoo removed, a surgical intervention which had cost him quite a lot of money and some minor discomfort. All he had ever known about the organization had been the other three names in his cell, but there must of course have been many more besides theirs, and above all an overarching command structure which no doubt reached up very far indeed into the military and political hierarchy. He had learned from an article in the press some years before that Alberto — now Colonel — Guerrazzi was now someone very high up in the secret services. Those people had unimaginable powers. If they felt threatened, as they undoubtedly must, by the potential disclosure of the truth behind Leonardo’s death, their response was likely to be immediate, pre-emptive, and totally unpredictable.