Then some of the letters went missing. At first it seemed a mistake, when a pretty slave in the house where Hadrian was staying offered to help clear one of his rooms, and his own fool of a freedman was too busy flirting to think. Partly that was Hadrian’s fault, for he usually burned anything dangerous as soon as he had read it, but on that occasion he had been called to the stables where one of his finest hunters was sick. That was sentiment for you, it always caused trouble. The host was apologetic, nervous when told that there was official correspondence among the missing letters – and there was, albeit a report on the sources of grain for the chief bases in southern Syria. The girl was put to torture, eventually admitting that a nice man in the agora had offered her money for any scrap papyrus, because he wanted to scrape it clean for resale. That might or might not be true, but the man was not to be found, and Hadrian was suspicious of chance. His agents were investigating the corruption in the provincial army at that time, which alone made him suspicious. Ferox knew nothing of all this, but Sosius had searched the property of the tribune he had killed and found one of the letters. In it, the criticism was mild, but there were others where Trajan’s mistrust of Hadrian was obvious, making clear that he was unfit for high office. Those were out there somewhere, and he had to suspect that they were in the hands of the men behind the corruption, waiting to be used at some point. Yet no one had approached him or threatened in any way. Sosius did not believe that the deserter Domitius had them, but had not been able to confirm this before the man was arrested. Even if he did not, then he might know more. Then there was Caecilius, bluff, very military Caecilius, who just might be one of the leaders or might just be too simple a soldier to have noticed the peculation going on under his very nose. Like everything else, this problem seemed to focus on Nicopolis.

Hadrian’s mind had wandered, and after a moment he realised that he had written the city’s name four times and then the word trust. He did not think Sosius had much to gain by betraying him, but then the man was such a good agent because he did not think in straight lines and had no scruples. Ferox was different, but experience suggested that it was unwise to assume the man only knew what he was supposed to know. Both men might just be coming to the end of their usefulness. Hadrian lifted the page to the lamp’s flame, waved it gently to speed the fire and watched it burn. One of the moths collided with the papyrus, scorching its wings and dropping onto the table.

‘Your own fault,’ Hadrian said out loud, and crushed it with the napkin.