Telamon had been gone a while, and still Hekabi hadn’t burst in to set Pirra free. She’d heard the clatter of hooves in the courtyard as Telamon galloped away, and after that, silence.

‘Hekabi?’ she shouted. ‘Hekabi, I’m in here!’

Where was she? Surely she’d only been biding her time until Telamon was gone? Or had he brought men with him, who’d caught her – or killed her?

From behind Pirra came a sudden agitated scratching of falcon claws. Echo might be bound, hooded and silenced, but she was frantically twisting her head this way and that. What new danger had she sensed?

A heartbeat later, Pirra smelt it too: fire. At the far end of the hall, smoke was curling round the doorway. With a sensation of falling, Pirra grasped why Hekabi hadn’t come. The wisewoman had set fire to the eastern storerooms and then, thinking Pirra had done the same on the western side, she’d fled the stronghold, as they’d agreed. She must be up on the spur, waiting for Pirra, quite unaware that she was still inside, bound hand and foot.

‘Hekabi!’ Pirra shouted at the top of her voice. But she was deep in the heart of the stronghold. No matter how loud she screamed, nothing could reach Hekabi through so many cubits of stone.

Wildly, Pirra cast about her. Telamon had taken her knife, she could see no other weapon. Then she remembered the spear on the floor at the other end of the hall.

‘I will come back for you!’ she told Echo fiercely as she lay down and started wriggling across the floor.

It was painfully slow, kicking with her feet and boosting herself forwards on her side, and by the time she was halfway down, she had to stop. Her breath stirred the ashes on the hearth. What a grim joke, she thought, that a fire that’s been burning for generations should have died just as the entire stronghold’s going up in flames.

She struggled on, trying to shut her mind to Echo’s panicky scrabbling. A pall of grey smoke was thickening above her and she could hear a muffled roar, as if a monster was attacking the stronghold. She pictured the storerooms engulfed in flames: all those man-high jars of oil. We’ll need great heat for the fire to take hold, Hekabi had said. And who would know more about setting a fire than she who worshipped the Lady of Fire?

At last, Pirra reached the spear. It was sharp bronze, but meant for jabbing, not sawing, and with her wrists tied behind, she couldn’t see what she was doing. The smoke was stinging her eyes and making her cough. At this rate, she’d never free herself in time.

Suddenly, she caught the patter of bare feet out in the passage. ‘In here!’ she croaked.

A figure appeared in the smoke.

Astonished, Pirra took in the sullen features of one of her Marsh Dweller guides: the mute boy she’d nicknamed Stone. ‘Quick, cut me free!’ she gasped.

The boy stood scowling in the doorway. He still wore his fishskin head-binding, but he’d washed the mud off his face and his features looked more delicate and childlike.

‘Hurry!’ shouted Pirra. ‘Echo’s tied up at the other end of the hall, we’ve got to get out of here!’

Still the boy hesitated. Something about him was oddly familiar: those eyes, and that tuft of barley-coloured hair poking out from his head-binding …

It can’t be, thought Pirra. Then she saw the knife at his hip – and the frog carved on the hilt.

‘Issi?’ she said.

Issi stared at Pirra with Hylas’ clear tawny eyes. Now that Pirra had realized, the resemblance was startling. Here was Hylas’ younger self – except that this girl was mute and suspicious, a child of eleven summers, scarred by too long alone and on the run.

‘Issi, please, cut me free!’

Still scowling, Issi drew her knife and set to work on Pirra’s wrists.

‘Why didn’t you tell me?’ said Pirra, rubbing the feeling back into her hands.

Issi ignored her and started on her ankles. The last rope snapped. Pirra tried to stand, but her legs gave way. She grabbed the doorway for support. ‘Fetch Echo,’ she gasped, ‘but don’t untie her till we’re outside, or she’ll panic and never find her way out –’

Issi shot her a glance that was incredibly like Hylas: Of course I won’t, I’m not an idiot! – then headed off at a crouching run under the smoke, returning soon after with Echo cradled in her arms.

Blindly, they staggered out into the passageway, into a nightmare of scorching black smoke. As Pirra held her breath, she tried not to think about Echo and whether she was still alive.

At last they burst into the courtyard: more roiling smoke, and a deafening roar. Bent double with her hands on her knees, Pirra took great heaving gulps of air. She saw Issi cut Echo’s bonds, then slip off the falcon’s hood and throw her to the wind.

Echo recovered in an instant and shot skywards. As Pirra watched her hurtle out of danger, some of the tightness in her chest snapped loose, and she breathed more easily.

Huge orange flames were pouring out of the storerooms and attacking the roof – but now, beneath the roar, Pirra caught the frantic screams of donkeys and horses.

She and Issi exchanged horrified stares. In Hekabi’s single-minded urge for vengeance, she’d forgotten to open the stable doors and set the animals free.

Pirra and Issi slid off the horse’s back and collapsed, coughing and retching in the grass.

Below them the roof of a watchtower caved in with a crash, sending great jets of flame roaring skywards. The horse squealed in terror. Hekabi grabbed the reins and tied it to a thorn tree.

‘That’s the last of them,’ panted Pirra on hands and knees.

‘Here,’ said Hekabi, tossing her the waterskin. Like them, she was covered in soot; when Pirra hadn’t met her on the spur, she’d returned to Lapithos, and found them desperately freeing the frantic animals.

Pirra gulped a mouthful, then passed the waterskin to Issi, who was crouching in the grass, blinking owlishly. In the child’s small pointed face, Pirra saw the same mute distrust as before. Except it’s more than that, thought Pirra in puzzlement, it’s almost – hostility.

She turned to Hekabi. ‘Have you known about her all along?’

‘Of course not,’ said the wisewoman, never taking her eyes off the blazing stronghold. ‘I told you, I thought the shadow thief was a boy …

Great charcoal thunderclouds were darkening the sky, lit from within by flickers of lightning – and yet no rain fell. The gods Themselves were letting Lapithos burn.

‘But did you really never suspect –’

‘While I was waiting for you,’ Hekabi cut in, still watching the fire, ‘I saw a Crow warrior on a horse: a boy, heading down the mountain. Was that Telamon?’

Another paroxysm of coughing seized Pirra: she could only nod. When she could speak again, she told the wisewoman what had happened in the stronghold. ‘Koronos is dead,’ she croaked.

‘Dead,’ gloated Hekabi. ‘My curse is beginning to work.’

‘Maybe – but Telamon has a plan. I’m not sure what he means to do, but he said that if it succeeds, no one will be able to reach the dagger – it’ll be safe for ever! He said …’ Again she broke off to cough.

Impatiently, Hekabi waited for her to go on. Even Issi crept closer to listen.

In bursts, Pirra told Hekabi everything Telamon had said. ‘He’s going to give it to his Ancestors. But what does that mean?’

Firelight danced in the wisewoman’s dark eyes. ‘The Ancestor Peak,’ she muttered. ‘Issi, you know Mount Lykas, is it true that above the tomb there’s a crack in the peak? A crack that reaches right down into the heart of the mountain?’

Issi nodded.

‘That’s it!’ cried Hekabi. ‘If he threw the dagger down there –’

‘We’d never get it out!’ exclaimed Pirra. ‘It would be safe with his Ancestors for ever!’

They stared at each other.

‘But he might not get his hands on it,’ said Pirra. ‘First he’ll have to find Pharax in the middle of the battle, then he’ll have to take it off him: how likely is that?’

‘True,’ said Hekabi. ‘But I have a feeling that he will. This has a whiff of destiny about it.’

Pirra’s thoughts raced as she watched Echo soaring overhead. If Hekabi was right and Telamon did get the dagger, they had to go up the mountain and stop him flinging it down the crack. But they didn’t know the way.

Suddenly, she snapped her fingers. ‘Issi knows how to get there! Issi, you have to take us … Issi? Issi!’

The hillside was empty. Issi was gone.