In amazement Silvius looked up from the roiling waves. A patch of white light was floating on the sea, which grew and expanded until it was splashing against his legs. He jumped backwards until he was on the shoreline once more, Elissa beside him.

From the centre of the light, a woman’s form was rising out of the foam. She was entirely naked, and her skin was like the sea, dark and rippling, speckled with starlight. Seaweed was draped around her shoulders like a scarf.

She raised her hand and pointed at Silvius. ‘You,’ she said, her voice like the surf. ‘You are his son. The son of Aeneas, who gave us life.’

‘What?’ He didn’t know what she meant.

‘The ships!’ called Elissa. ‘The ships! It’s true! The Trojan ships that turned into sea nymphs!’

Silvius remembered. When the Trojans had reached Italy, their boats had been blessed with divine life, in recognition for their service.

‘Apollo calls to me from on high, and I hear him. He still watches you mortals. Many of my sisters have gone now, through a gate into another world.’ There was a deep sadness in her voice which touched Silvius. ‘Yet for you, I will, for a time, renounce my new form, and return to the shape of a ship.’

She swam back into the sea. There the nymph drew her arms together into a point, and bowed forwards. Her eyes closed, and her body creaked and groaned and grew larger, turning entirely wooden; and then she rose out of the swell. The rush of waves that followed caused Silvius to fall flat onto his back in the surf, and he watched, open-mouthed, as a small, beautiful sailing boat raised itself from the harbour waters.

It gleamed dark grey like a dolphin’s skin, the beautiful carved form of a woman as its figurehead. She spoke once more, though her lips did not move. ‘Climb on now, and we will go.’

Iulus and his companions were watching in wonder. One of them had brought out a net of the sort used to catch deer, and was preparing to throw it. But Iulus stopped him, gripping his wrist.

‘Let him go,’ he said, thoughtfully. ‘Let him go.’ He called across to Silvius, ‘Be strong, little brother. Be strong. You will need it.’

Silvius turned, and held up his arm in farewell.

Elissa had already swum out to the ship and was clambering up the rope ladder, the pack and the wolf cub on her back. She turned to look at Silvius, eyes alight. ‘Come on!’

Silvius splashed into the waves, and gasping from the cold, swam as powerfully as he could to the bottom of the ladder, and then, panting and soaking wet, he toppled onto the deck next to Elissa. He was filled with a sense of lightness. He steadied himself on the rail that ran around the ship.