Hadrian drank his share, but he remained focused on the part he was playing. He was good at detail; Brigonius heard him sympathise with one unit of mixed cavalry and infantry that it was harder for them to put on a spectacular display than for a dedicated cavalry unit with their larger numbers of horse. Each man seemed to grow in his presence, and Brigonius could see why he was so loved by his troops.

It wasn’t a bad life, Brigonius was coming to think, to be a soldier of Rome. You received regular pay and reasonable food. You had camaraderie in the barracks, and there was always the civilian town outside your fort, with its shops and inns and brothels and temples, where you might find a little relief, or a companion who could one day become a wife. The barracks could be rife with lice, and the town with diseases. But you could get rid of the lice in the bath house, and if you got sick you could go to the hospital - the army ran the only professional hospitals in the world. You might go through your whole twenty-five-year career with only two or three campaigning seasons, and perhaps without seeing any fighting at all. You were almost certainly better off than the Brittunculi or other half-civilised provincials beyond the walls of your fort ... And every so often an emperor came to visit.

Many of the troops had grown beards, in defiance of the usual Roman custom, imitating Hadrian’s coin images. This amused Severa. ‘Look at them. The Emperor’s beard is more famous than he is!’

At noon the Emperor and his retinue, with Brigonius and Severa in tow, retired to the fortress’s headquarters. Today the largest reception room in the block had been decked out as a shrine to many gods, and the party settled down to a long afternoon of eating, drinking and fortune-telling. At the inception of his mighty project Hadrian was seeking good auguries. Since dawn his philosophers had been inspecting the sky, looking for unusual clouds and the flight of birds with auspicious patterns. Now animals were put to death on charcoal braziers, entrails were prodded, statues venerated and libations poured, as scholars worked their way through scrolls of prophecies and interpretations.

Only the sinister freedman Primigenius sat aloof from it all, as always watching, watching.

With Severa at his side like a gaoler, Brigonius had nothing to do but drink. The chanting of the philosophers and the thickness of the air, cloudy with incense, made him feel as if he were floating out of his body. He tried to strike up conversation with Severa. ‘Romans are always superstitious, aren’t they?’