Tullio growled, 'My cock is an imposing statement, but that won't stretch from sea to sea, and neither will this Wall. Look, friend, let me put you out of your misery.' He took a notebook, a fat block of wood, and shook it out into a strip of leaves hinged at their edges. He dipped a pen in ink and briskly began to scribble numbers. 'Seventy-one miles, you say? Ten feet by fifteen? If there are, um, so many feet to the mile…The point is, friend, I've worked with legionaries. I know how much stone or earth a man can shift in a day…' He came to a result; he tapped the wood leaf with his pen. 'To haul all that stone from the quarries to the Wall line will add up to about twenty million legionary work-days. We'll have fifteen thousand legionaries at most, and each man can manage perhaps two hundred days per year-less this year, as it's June already. And if you divide one number by the other-yes, here we are-you'll find it is going to take you over six years to build this Wall. Not three!'

'But-'

'No buts. Look at the numbers!' Tullio threw his notebook at the architect. 'Oh, it's always possible to shave off a bit. Use only local stone. Push the legionaries that bit harder. Maybe make some use of local labour or slaves, but if they're untrained they won't be useful for much. But none of that will make any real difference. No, I'm saying you simply can't do it, friend.'

Old Xander seemed about to burst into tears.

Severa glared at Tullio. 'I don't know why we're even having this debate. The command for this Wall comes from the Emperor Hadrian himself.'

Tullio sat back and folded his massive arms. 'I don't care whether he's the Emperor of the Romans or the King of the Bog People. You can't build a six-year Wall in three years, love.'

Severa's fury was cold. 'Don't you call me "love", you fur-backed-'

'Severa!' Karus snapped.

Annius was studying the model. 'Tell you what. Why not build it in turf? Just as good at keeping out the hairy lads from the north, and be done in less than half the time.'

'Turf? Turf?' Severa said menacingly. 'Why, you insolent fool, if I had a clod of turf in my hand right now, I would gladly shove it down your throat-'

Brigonius touched her arm. 'Wait,' he whispered. 'I'm a quarryman. I deal with fellows like this all the time. It's all a game. Just give us some time.'

Karus stood hastily. 'Quite right. Let's sleep on it, shall we?' He stood massively over Severa until she allowed herself to be escorted from the room. Then he sat down, blowing out his jowled cheeks with relief.

'Feisty piece, isn't she?' Tullio said.

'You don't know the half of it,' Karus said dryly.

Brigonius faced Tullio. 'Let's get down to business, shall we? You heard her, prefect. This is the Emperor we're dealing with. And the Emperor wants a stone wall.'

Tullio said heavily, 'Listen, black-beard, the Emperor can want to build his Wall on the moon, but that doesn't mean it can be done.'

'Then what can you do?'

Annius was pulling his lip. In his dull way he seemed the more creative of the two, Brigonius thought, and was at least trying to come up with solutions. 'Tell you what,' he said slowly. 'How about half in turf and half stone? You could probably manage that in the time. Then you get the best of all worlds, a complete defensive barrier in three years and a nice bit of stonework to impress the boss.'

Brigonius was about to reject this out of hand, but Xander said wearily, 'Four-tenths.'

Brigonius turned to him. 'What?'

'Not half. Four-tenths in turf, the rest stone according to the plan.' He tapped Tullio's notebook. 'That is feasible from the figures, if you are honest in your calculations, prefect. Besides I worked it out for myself earlier.'

Tullio took back the notebook and revised his figures quickly. 'All right. Yes, four-tenths turf, six-tenths stone. Yes, you could do that.'

Xander turned to Brigonius. 'This is the best we can do in the time.'

Karus said darkly, 'And you knew this before we came in here? Why didn't you say something when we put the plan before the Emperor?'

'Because I didn't know we would only have three years,' Xander said. He sounded exhausted. 'Severa didn't let slip that little detail until the audience. What could I do, argue with her before Hadrian himself?'

'It's not so bad,' Annius said cheerfully. 'Everybody goes away happy. And you could always replace your turf with stone later.'

Karus growled, but subsided.

Brigonius glanced around. 'All right,' he said cautiously, not wishing to overstretch the consensus. 'Then the question is, which half will be turf?'

After another hour's discussion, and after a tankard or two of Tullio's coarse German beer, they came a conclusion. From Segedunum at its eastern extremity, the Wall would run west as stone for forty-five miles, and then turf the rest of the way to the western coast. The eastern half of the Wall was closer to local sources of good stone-not least Brigonius's own quarry-and the two soldiers regarded the security situation along this part of the border as more critical, so stone was appropriate for this stretch.

'And besides,' as Tullio pointed out, 'the eastern half is where the Emperor is. He's going to want to lay a foundation stone, not dig a lump of sod.'

The four of them stood up and shook hands. 'Then we have a plan,' Brigonius said, weary but relieved. 'Now all we've got to do is sell it to the Emperor.'

'That's the easy part,' Karus muttered. 'It's Severa I'm frightened of…'

The climax of Hadrian's visit to Eburacum was the twenty-fourth of June, a day of religious celebration for soldiers wherever they were posted across the empire. After this Hadrian would ride north and ceremonially install the first foundation stone of the great Wall which would soon divide the island of Britain in two.

Brigonius had been forced to learn a lot about the habits of his sole customer, the Roman army. A soldier's religious life was complicated. To begin with he brought along his own gods. A German here in Britain, for instance, celebrated his feast of Matronalia on the first of March. He would also be expected to pay respect to any local deities. The soldiers seemed to like Brigantia's own Coventina, and thanks to the army's mobility she was gaining adherents even overseas, in Gaul and Germany. But the soldiers' statues of her, crudely made, were alien in the eyes of the Brigantians, who found Coventina in the hills and the streams and in the wind, and did not recognise these busty Romanised cartoons.

The centre of a soldier's religious life, however, was a calendar based on feasts of the traditional Roman deities, principal city days, the anniversaries of the emperors, and dates associated with his unit itself. And of all the feasts on the calendar none was more significant than today, the twenty-fourth of June, the feast of Fors Fortuna, a popular goddess among the troops.

Brigonius had hoped to spend the day in the company of Lepidina. He wasn't sure what Severa's plans would be now, and how much more time he and Lepidina would have together. But as the day's festivities began Lepidina was nowhere to be found.

Then Severa herself peremptorily requisitioned him as an escort. Beside Severa, her face set as hard as Roman concrete, Brigonius found himself trailing the Emperor as he toured the troops.

Accompanied by his courtiers, Hadrian walked slowly from barracks block to training field, and inspected displays of infantry field manoeuvres and formation riding by cavalry units. It was a festival day, and the imperial party grew raucous on wine and British beer. Brigonius had a policy of staying sober around Romans, but Severa seemed determined to ply him with drink, and he saw no point in defying her. As the ale filled him even her company seemed less than icy.