They were working in one of the streets of Lavinium, just by the blacksmith’s, where his boy was busily at the bellows, face grimy with soot. People bustled in and out of the long, low wooden houses on one errand or another.

The two young men who’d been in charge of that day’s supplies for the fortifications paused in their work and wiped their hands on their tunic hems. ‘It’ll do,’ said one. ‘But can’t you find something to do in the palace with the women?’ He spoke indulgently, and Elissa smiled winningly back at him. She was about to make a suggestion telling him exactly what she thought of sitting around weaving all day with the women, when she heard the voice of her friend, Silvius, calling through the gathering darkness.

She winked at the carpenters, stopping to take the last glistening, juicy olive from a bowl that lay on a bench, and ran to see what was happening. Above her, a comet blazed through the sky, and she watched it disappear over the city walls.

Perhaps it will land somewhere, she thought. Perhaps it had flown over her mother’s home, Carthage, far across the Middle Sea.

She sent her wishes with the comet: that she might meet one of her own people soon, that she might discover more about her mother’s life.

There was a commotion ahead of her, and she heard Silvius’s voice calling out to all. ‘Be well! We’re going to Aeneas. Be well!’ There was something, a note of alarm, in his voice that surprised her. She’d heard the horn earlier, and wondered if it might have something to do with that. Soldiers were looking on with suspicious expressions.

She came upon the procession. It was a strange sight; a straggle of people, faces indistinguishable, the moon’s light partly obscured by clouds.

But nothing was stranger than the beast that was walking next to Silvius. A flutter of excitement raced through her. Could it be? A few nights ago, the girl she shared her room with had woken her up from a dream Elissa hadn’t been able to make sense of. The flash of chestnut flanks. The fletch of an arrow. And a man, joined somehow to the horse.

It was her dream, coming towards her.

Dwarfing Silvius, the centaur’s torso rose higher than the tallest man Elissa had ever seen. Letting out a whoop, she ran skipping towards them, one sandal loose, and, ignoring a warning glance from Silvius, approached the beast as near as she dared.

The centaur paused, and behind him all the large crowd of followers they had attracted.