‘You and your mission,’ snarled Iulus. ‘You’re making a lot of trouble for us. Apollo! As if, even if he were here, he would ever choose to speak to you. It’s probably a delusion.’

‘I’m not coming back,’ said Silvius, coldly.

‘Too late,’ said Iulus, and he pointed down the road. There, moving at a steady canter, were a group of about a dozen of Iulus’s hunting companions, all mounted on good, strong horses.

Silvius caught Elissa’s eye. There was nothing they could do. They had been stymied at the first hurdle.

Suddenly Elissa broke away and ran headlong to the harbour, Ruffler bounding at her heels, with Silvius not far behind.

‘What, are you going to swim away?’ called Iulus after them.

Silvius splashed into the freezing waves. ‘There must be a boat here somewhere, a rowboat or something,’ he said to Elissa. ‘Can you see anything?’

‘I’ll try over here,’ called Elissa.

‘Keep looking!’

Iulus laughed, his hands on his hips. ‘Give it up now, Silvius. Give it up. I almost admire you, little brother. You must get that from Aeneas, not from your Latin mother.’

The insult burned through Silvius. He knelt in the waves, his mind listing from side to side. ‘Apollo,’ he whispered. ‘Apollo, please help me.’

‘Those peasant Latins, living like beasts in their huts. I’m the only true Trojan,’ Iulus spoke harshly.

Silvius was trying to pray, trying to see Apollo and feel his light. But he kept noticing the weight of the Arrowhead. Again the strange hissing noise at the edge of his hearing. The casket wanted to be opened. Stargazer had said destroy. And it had worked. His fingers moved towards it. Surely he could not use it against his brother, his brother’s people. It burned against his skin.

From somewhere far off he heard Elissa. ‘No, don’t!’ she called. ‘You can’t do that! You’ll kill us, kill us all!’

She was kneeling beside him in the waves now, and her hand was on his arm, and he saw her quick eyes shining in the moonlight. He let his hand drop, and caught hers.

Iulus’s men had reached their leader, and a few of them had dismounted to watch.

‘Apollo, please …’ called Silvius now, stronger, trying to drown out the hissing that was swelling around him. Was that a snake in the water, twisting towards them?

Elissa joined in. ‘Apollo, please, we pray to you!’

Then they were both calling, ‘Apollo! Apollo!’ until the name was just a string of sounds, blurring and falling over each other.

‘Go on,’ Iulus was commanding. ‘Go in and get them.’

Apollo wouldn’t come. Silvius knew it. The water was boiling now, and he could see sea snakes everywhere, curving and sinuous, circling and getting ready to strike. Elissa gripped his hand tighter. ‘Come, Apollo, come!’ Her prayer sounded weak.

And then, from all around, a deep voice, answering them.