They fell in with the soldiers around Helenus. There was a moment of calm. Shouts came from all over the plain, and the hissing of the Enemy was loud.

‘Lock shields! Two above.’ She held hers above her head, and Silvius, getting the idea, did the same, so that they had protection above them, and Tisamenos went in front of them with the Last Gorgon’s head in his left hand.

The Enemy were concentrating on Helenus and his band, and Tisamenos turned the gaze of the Gorgon on them as they attacked. As each one became stone, Tisamenos’s face seemed to harden too, his eyes glazing over. It made Elissa fear for him. But they had to press on. She saw that they were now nearing the seething darkness in the centre.

The Achaean soldiers behind them were faltering, swallowed up by the horror of the Enemy. A distant shout told her that Orestes was sending in the second line. Helenus yelled, ‘Onwards!’

His band charged forwards. Elissa and Silvius kept in step behind them.

The confusion of battle was all around. She jumped over bodies on the ground and could not tell if they were Achaeans or Enemy.

In front of them, Callias came to blows with two children; Tisamenos turned one of them into stone, but they were not quick enough to halt the other, and the Enemy child ran Callias through with his sword. ‘Callias!’ Silvius was distraught, Elissa could see. But they could not wait; they could not even stop to tend to him.

The hissing of the Enemy was filling the air from all around. It urged Elissa to put her weapon down. But she fixated on the light of Helenus, the light of Apollo, and on Silvius, and then on Tisamenos. He was pushing onwards. She had to push on too.

The Enemy ranks were dropping away from them, running to pick off the Achaean soldiers behind them. Elissa thought she heard the voice of Orestes. ‘Keep fighting!’

Now Helenus paused, and the white light from his forehead shone bright. ‘There he is,’ said Helenus, awe and terror in his voice.

Ahead of them, spiralling, vast, was the great serpent Python.

A shiver of terror rushed through Elissa, and she felt small and vulnerable. How could they defeat this beast? It was impossible. In his scales, in his fangs, in his glowing red eyes, there was a power that would consume the world.

And what could she do to prevent that?

Her hand went to her neck. There was the little dolphin pendant her mother had given her. She hadn’t known her own mother, but that didn’t mean that others couldn’t. If Python succeeded, there would be no more little girls playing with their mothers’ hairbrushes, teasing their kittens, throwing pebbles into wells. She glanced at Silvius beside her, and saw that he too had been overcome with revulsion. Tisamenos was upright, the only one of them not trembling.