Though always favoured by his commander Vespasian, and despite his little bit of notoriety following his time in Britain, Marcus Allius had never risen higher than centurion-nor, if truth be told, had he ever wanted to. He retired from the army as early as he could on a fat veteran's pension, and bought himself a compact little vineyard a day's ride from his native Rome. Just as he had always been a competent but never great soldier, so he proved a prosperous but never rich vintner. He raised a strong son who followed his father into the army.

Aged fifty-five, over a quarter of a century after his British adventure and as healthy as he had ever been, Marcus looked forward to a long retirement.

Then, one day, a slave sought him out bearing a letter.

The note was from one Agrippina, British-born but resident in Rome. She had been present at the Roman landing at Rutupiae too, she wrote, and her letter concerned 'unfinished business'.

She had been able to consult Vespasian's official biographer to find out which legion had been the first to land in Britain, that dark night in Rutupiae thirty years before, and which century had landed first, and which man of that century had been the first to set foot on British soil, whose name she thought she had heard. Agrippina summarised the steps she had taken to ensure that she and she alone took full responsibility for the crime that was about to take place-but she would already be dead by the time Marcus Allius opened the letter.

Marcus looked up at the slave, to ask, 'What crime?'

The blade in the slave's hand was the last thing he saw.

Brigonius agreed to meet the women from Rome outside the town of Durovernum Cantiacorum, on the road leading east towards Rutupiae at the coast.

For a Brigantian it was a long way from home. But Brigonius reached the rendezvous early in the morning, well before the appointed hour, and had to wait. He found a milestone to sit on, set his battered old wide-brimmed hat on his head to keep out the sun, and let his horse chew on the tough, dirty grass at the roadside. As the day wore on he grew hot, his face itching under a beard still new enough to be a novelty. He was twenty-two years old.

He was maybe half a mile down the road from the town. He inspected the place curiously. Durovernum was an island of wood and stone, of roofs of bright red tiles. It looked very strange to Brigonius, not at all like his own community of roundhouses at Banna-and nor was it like the Roman military architecture he had grown up with in the north, the endless box-shaped forts and watchtowers, like the one in Banna.

He was used to Roman roads, though. The whole country was carpeted by them. This one ran straight as an arrow's flight off to the east, its hard-packed gravel surface pressed flat. His quarryman's eye noted how it had been resurfaced two or three times, so that it was raised proud of the surrounding farmland. Old or not the road was well kept, its drainage gullies swept clear, and with no sign of subsidence. The Roman soldiers who first built this did their job well, he grudgingly admitted.

But it wasn't soldiers who used the road today. For perhaps an hour in the early morning Brigonius was at peace, just himself, his horse, the road and the songs of the birds. But as the day wore on the road filled up with traffic: people on foot and horseback, or riding carts and wagons and litters. The townsfolk were bright, clean, well-fed, their clothes were brilliantly coloured, and their skins shone with cosmetic oils. Slaves walked beside their masters' carriages, or carried them on litters and chairs. Everybody was streaming east. It was as if somebody had tipped up the town and poured out its inhabitants like oil from a pot, spilling them towards Rutupiae, where the Emperor was due to land today.

Sitting on his stone beside this glittering crowd, Brigonius felt out of place, an ill-formed northern clod. But he had been summoned here, he reminded himself.

He took Severa's letter from his satchel and read it over again. It was written in a blue dye on a small, scraped-thin rectangle of wood, scored down the middle and folded over. His own name was written on the outside, with an address: Vindolanda, the large fort planted square in the middle of Brigantia, with which Brigonius did a lot of business. Inside, the Latin text had been written out in two orderly columns by a neat, somewhat cramped hand. But it opened with a generous greeting-'From Claudia Severa to her friend Brigonius, greetings'-and signed off with a flourish-'In the hope that this finds you in as good health and fortune as I and my daughter enjoy, C. Severa'-both in a different hand from the main text, which had presumably been written out under dictation by a scribe.

Brigonius was literate. He needed to be. His father had died two years ago, leaving Brigonius, at just twenty, in sole possession of the family quarrying business. His main customer was the Roman army, who devoured cut stone for their forts and roads, their shrines and bath houses. And the army was a hive of writing, writing, writing; a soldier couldn't fart, it seemed, without some junior officer making a note of it.

So Brigonius was used to letters. But he had never received such a letter as this before. For one thing it had come all the way from Rome: a letter from Rome, addressed to him. His correspondent, Claudia Severa, lady of Rome, claimed a family connection to Brigonius, saying that an ancestor of hers had once known an ancestor of his.

And the letter spoke of the Emperor's coming visit to Britain. That was no news; everybody had been talking about it for months. But, Severa said, the visit would give their two families, Brigonius's and Severa's, the chance to grow very rich indeed. How did she know all this? Because of a prophecy, she said.

It was hard to know how to take all this. The mention of profit got his attention, but he recoiled from the talk of family histories and prophecies. The superstitious Romans were obsessed with past and future, with dead ancestors and presagings of time to come. Better to live in the present, he thought, and enjoy the now. As time wore on and he sat on this milestone with the smug Cantiaci citizens bustling past him, he wondered if he was wasting his time.

But then the two women arrived. And within a heartbeat of his first meeting with Severa-or rather her daughter, Lepidina-all his doubts were dispelled.

Claudia Severa and her daughter arrived in a small carriage covered by an awning of bright red cloth. A servant, probably a slave, led two docile horses. Severa and Lepidina stepped down from the carriage with unreasonable grace, and walked towards Brigonius. The mother might have been forty, the daughter eighteen or nineteen. The two of them were very alike, both very pale, with strawberry-blonde hair piled high in exotic sculptures.

The older woman wore a stola, a swatch of brilliant white cloth embroidered with purple. Under her loose clothing Severa's figure was shapely, her bust prominent and her hips swaying as she walked. She was sensual, but she looked solid, almost muscular. This was a formidable woman, Brigonius thought immediately.

The daughter, though, was slighter, slimmer, and she walked with a loose-jointed beauty. She wore a long skirt and tunic of pink and silver-grey, the colours somehow blending perfectly together, and she wore a scarf around her neck, some purple-pink fabric as light as mist. She was so delicate, so pale-white, she seemed only loosely attached to reality. Again he felt like a clod with his black hair and dark colouring, a lump of earth compared to this creature of air and fire.