Regina gasped at this language, shocked and delighted, and Carta colored.

“But we fought back. While the Emperor Claudius was still in Britain, one of his generals, Vespasian, had to fight his way west, taking hill fort after hill fort, supported by the fleet tracking him along the coast. It was a mighty feat of generalship — and later Vespasian himself would become Emperor — but, by my eyes, we made him earn that throne. And that is why the men of the Durotriges became such good soldiers for the Empire.”

“Like you, Grandfather.”

He said gruffly, “You’d have to count my lumps. But, yes, I’ve been a soldier all my adult life. As was my father, and his before him. But things have changed. There have always been barbarians—”

“In the north, and beyond the sea.”

“Yes. They aren’t soldiers but professional savage fools, farmers, bound to the land. They could not even mount a genuine campaign. They were no match for the Empire — not until the barbarica conspiratio.”

It had come more than forty years earlier, a great barbarian conspiracy, a coordinated attack on Britain by the Picts across the Wall from the north, the Franks and Saxons from across the North Sea, and the Scotti from Ireland. Defenses designed to hold against an attack from any one of these enemies had been overwhelmed. There was much muttering of espionage, for the British military commanders on the northern frontier and the coasts were ambushed and killed.

“It was a terrible time,” Aetius muttered. “I was not fifteen years old — no older than you, Cartumandua. For a time the countryside was full of roaming bands of barbarians — and, I have to say, of deserters from the army itself. Even Londinium was sacked. It took the Emperor two years to restore order. My own view is we’re still trying to recover from that great shock.”

Carta spoke up again. “Sir, she is only a child.”

Aetius said grimly, “She needs to hear it even so, Cartumandua, and to hear it again until it sinks in. Let me say this. Six years ago I was on the Rhine — Gaul’s great river frontier. In the middle of winter it froze over, and into Gaul swarmed the Vandals and the Alans and the Suebi and Jove knows who else. They just walked across the damn river, as cool as you please. We couldn’t hold them — we fell back and fell back. And they are still there now, crawling around the prefecture, far inside the frontier. I was glad to get a posting back to Britain and away from all that, I can tell you … I suspect this poor child will spend much of her life seeking a place of safety.”

Regina sniffed. “This poor child understands every word you say, you know.”

Aetius looked at her, astonished. Then he laughed, and clapped her on the back. “So now I’ve got you to contend with, as well as the Vandals and the Picts and the Saxons …”

“Look.” Behind Regina, Cartumandua stood up and pointed. “I can see it.”

Aetius reined in the horses. Regina stood on her seat, shielded her eyes with her hands, and stared until she saw it, too.

A line of darkness stretched across the world, from one horizon to another, rising and falling over the contours of the moorland. Along that line, smoke rose up everywhere, and mud-colored buildings huddled. Suddenly she knew exactly where she was, exactly how far she had been brought: from one end of the country to the other.

She wailed, “ It’s the Wall. What are we doing here? Aren’t we going to a villa, or a town?”

“No,” said Aetius grimly. “This is where we will live now, here at the Wall. It won’t be so bad—”

“This is a place for dirty, stinking soldiers. Not for me !”

“You’ll just have to make the best of it,” he growled warningly.

Carta hugged her. “Don’t worry, Regina. We’ll be fine here, you’ll see.”

Regina sniffed. “We won’t be here forever, will we?”

Carta looked at Aetius. “Why, I—”

Regina asked, “Just until things get back to normal?”

Aetius looked away.

Carta said, “Yes. Until things get back to normal.”

Regina looked about more brightly. “Where’s my mother?” None of the adults would reply. “My mother isn’t here, is she?”

Aetius sighed. “Now, Regina—”

“You promised me.”

His mouth opened and closed. “Well, that’s jolly unfair. I promised no such thing.”

“Liar. Liar. ”

Carta tried to subdue her. “Oh, Regina—”

“She doesn’t want me. She’s sent me away.”

“It’s not like that,” Aetius said. “She loves you — she will always love you. Look — she asked me to give you this.” From a fold of his tunic he produced the precious silver dragon brooch.

She dashed it from his hand; it fell to the coarse grass, where it gleamed. She turned on Cartumandua. “And don’t you dare pick it up, Carta! I never want to see it again.”

Cartumandua flinched from the command in her voice.

And that was when the tears came, in a sudden flood, sudden as a rainstorm. Aetius folded her in his arms, and she felt Carta’s small hand on her shoulder. She wept for her mother and herself, as the carriage clattered its way the last few paces toward the Wall.

I took Vivian’s advice and set off in search of my sister.

I booked some overdue leave. I had no trouble getting it through my line manager, or even through the Nazi killer robots who ran Human Resources. But I saw the way their gazes slid away from me as I handed over the forms and explained my vague plans. My days at Hyf were numbered. To hell with it.

I drove north, listening to news radio all the way. Along with the sports and the useless traffic bulletins, the main topic of the day was undoubtedly the Kuiper Anomaly. Absorbed with my own affairs, I just hadn’t noticed the way this thing had continued to mushroom in the public consciousness.

Reaching Manchester at around ten that evening, I drove to the city center, to the hotel I’d stayed in before. I actually parked the car. But I didn’t get out. I remembered what Vivian had said: reconnect. I shouldn’t be here.

I turned the car around and drove out to the suburbs. I canceled my hotel reservation with my cell phone.

There was a real estate agent’s sign outside my father’s house. I hesitated to disturb Peter, but when I knocked on his door he was awake — I heard the hum of PC cooling fans; perhaps he was working — and he was happy enough to give me a key. I let myself into Dad’s house. Inside it was warm and clean, but of course it was stripped of furniture; somehow I hadn’t been able to imagine it this way. There were pale patches on the wallpaper where furniture had stood for years. Empty or not it still managed to smell musty.

To my chagrin I finished up knocking on Peter’s door again. I borrowed a sleeping bag, pillow, and flask of tea. I spent the night on the thick carpet of my old bedroom. Lulled by the sound of distant trains passing in the night, immersed in a familiar ambience, I slept as well as I had in years.

In the morning, around eight, Peter showed up. It was a bright, fresh morning, the sky a deep blue. He brought soap, towels, a glass of orange juice, and an invitation to come over for breakfast. I accepted, but I promised myself I’d get to the shops and stock up as soon as I’d eaten.

Set on the other side of the road, Peter’s house was a mirror image of my father’s, the staircase and rooms eerily transposed from left to right. I went in there with some trepidation: this was the domain of Peter the solitary weirdo, after all. Well, it was plainly decorated, so far as I could see, with bland pastel paint hiding old wallpaper. The furniture looked a little old, and certainly wasn’t modish, but it wasn’t shabby. There were bookcases everywhere, even in the hall. The books seemed neatly ordered, but not obsessively so.