For answer he beckoned her, and tiptoed out of the room. Of course, she followed.

Amator had his own chores to complete. Carausias was trying to train him to run the villa, the cause of much conflict between the two of them. But he always seemed to have plenty of spare time, and he seemed happy to spend a lot of it with Regina. When he discovered she liked “soldiers” he proclaimed himself an expert, dug out an old set from some corner of the house, and set it up in the courtyard where they would play. Or he would play ball-catching games with her, or simply chase her through the colonnades, or in the open spaces beyond the town walls. Gradually, almost tentatively, a relationship had built up between them.

But there was an edge to Amator. At eighteen he was so much older than she was. Perhaps she enjoyed the undercurrent of danger that she sensed about him, a boy who knew so much more than she did, had surely done so much more, and yet was so inexplicably interested in her. Amator was mysterious, disturbing, somehow enchanting—but above all he was fun, and he always seemed to dress with color and style, unlike the drab townsfolk.

Cartumandua maintained a frosty silence about all this.

They walked around the courtyard until they came to the head of the stone stairs that led to Carausias’s shrine.

She stepped back. “No. I mustn’t go down there. Carausias wouldn’t like it.”

“Well, Carausias doesn’t like being bald and fat and old, but he’s got to live with it. Come on—unless you’re scared.” He set foot on one step, then another, and was suddenly trotting down and out of sight.

After a heartbeat’s hesitation, she followed.

The shrine was just a pit in the ground. She could hear Amator scratching, and then he held up a candle. His face seemed to hover in the dark.

In the uncertain light she could see that above the stonework of this little underground shrine there was a layer of darker earth. When she probed at it, it crumbled, and left black on her fingers, like soot. Later she would discover that twice during its short history Verulamium had been burned to the ground, and these burned ash layers were relics of those catastrophes.

An arched hollow had been cut into the wall. In it stood a little statuette, apparently bronze, of a man riding a horse. His outsized head bore a crested helmet. Small offerings had been laid out before him, perhaps fragments of food.

“Behold,” said Amator mock-sepulchrally. “Mars Toutatis, the warrior god of the Catuvellauni. Held to be the Mars of Rome, while that was politically convenient. What now—do you think he will become the Christ? Will we have to carve a chi-rho above his head?”

“You shouldn’t talk like that,” she whispered.