She stepped close to Sulla and whispered, “You can join us.” You and Amator’s legacy, she thought. “But first you must free yourself.” Sulla looked confused. She let a knife fall from her sleeve—a knife she always carried in these difficult times—and slipped it into his hand. “Free yourself.”

His eyes widened. He nodded and pulled away.

Castor approached Regina. “Is Brica—”

“She is safe.”

He nodded. “Soon I will be with her.”

“No. I have an assignment for you. When the last of us has descended, close the hatch and cover it over with turf. Move the furniture—a table, a couch—conceal the entrance. Do you understand? I know it means you will be kept apart from Brica. But it is the only way she can be safe. She is counting on you, Castor.”

His eyes narrowed, and she wondered briefly if he read her calculation: that despite the marriage only that morning, already she was separating him from Brica, drawing her back into the family. But he nodded, and he hurried to help the elders usher the children to the shaft.

Regina stayed by the trapdoor, helping the students descend into the dark, until she saw Sulla embrace Amator—and Amator fell to the ground, unnoticed in the chaotic confusion in the garden—and then, as the smoke of the fires grew thick in the air, she clambered down into the ground herself.

The Vandals remained in the city for two weeks. They invaded the homes of the rich, broke into the Christian churches, stripped the gilded tiles from the ancient Temple of Capitoline Jupiter. And they murdered, maimed, and raped Romans both high and low.

Regina had prepared for a siege. She had installed a lead-pipe feed from the main water supply, and there were caches of food—dried fruit, meat, nuts. Even if the trapdoor entrance in the peristylium was discovered and broken open, the Catacombs were a warren that extended far underground, and there were many places where the tunnels could be blocked off and defended. There was even another tunnel that led out of here altogether to one of the main city sewers, out of which they could find a way to the daylight. It wouldn’t be a pleasant journey, but it would lead them to safety.

Stuck in these soot-stained tunnels, it wasn’t a happy time for anybody. But despite their protests at deprivation, fear for their families, and plain discomfort in this place of corpses, Regina knew that her charges accepted that she had delivered them to safety, out of sight of the black-painted monsters rampaging above.