Ruidic's eyes sharpened on her, their ever-moving greens and blues troubled.

"I didn't see myself saving us, Grace. I saw you."

"And what was I doing?" she asked him, so absolutely certain that she was right that she knew his answer would confirm it.

"You were..." he broke off, and waved his hand in frustration, frightening the dragon-fly away. "It's hard to explain, because when I see, which is not often, it's all strange images which I have to interpret. But you were powerful, and you knew something that would save us..."

"It was understanding, that's all," Grace said, gently. "I could understand enough to tell you what to do. That was the power."

He shook his head, and made to protest again, but she insisted, "Look again. See if you can see now."

He gave her a wry smile. "You think it's as much under my control as that?" But at her determined expression, he shook his head with a sigh, and looked away from her, into the distance. For a moment, his eyes flashed a strong golden-green, and then he blinked, and gave a small sigh.

"All right," he said. "All right."

He looked out at the city, and seemed to be seeing something else. Whatever it was, it brought the same sadness to his eyes there had been when he sat with Benjamin.

Grace tried to smile at him, even though her own disappointment was a strong and bitter note in her mind.

"You get to be the hero," she said, "and in a weird kind of way, it suits you."

She was relieved to see him give one of his smirks, and looked back at her.

"Do you think you can tell me what to do without patronising me?" he asked her, mocking a little.

"I can't promise anything," she said, and then she stepped up to the glass again, sharpening her eyes on that army once again. They weren't far from Naian now, but the cold creatures had almost reached the wall. There were only minutes until they would pour over, and the cold mage would be here soon, too.

"You need to cast a living spell," she told him, as quickly and as clearly as she could. "It's something that will make sense to you, I think. All these plants and animals have life in them, and you undertand it. But this spell needs to be strong and complex enough to protect the whole kingdom."

Ruidic gave a snorting laugh. "There has never been a living spell that complex," he said.

"Yes there has," she told him, firmly. "That's what Cartheno's Fire was. A living spell, of the kind you understand without even having to try." She nodded out to the kingdom beyond the pane of crystal. "I don't know how, but this whole kingdom was built for this spell. It's been waiting for it. Every city has been built around roads that make up one of the thirteen symbols."

She pointed to Naian. "The symbol of revealing," she said. And she gestured to Jiescek. "The symbol of turning." And then she turned so that she could see Osciem. "The symbol of breaking."

She watched as Ruidic studied those cities, and an expression of wonder came over his face. "They've been this way for thousands of years... all for now?" he shook his head. "Who could have done that?"

Grace shrugged. "Someone with sight like yours, I guess All they needed was to see there would be danger here one day. And that's not so hard to predict in a world where there are nightmares and evanescents."

He held his hands out to the glass and traced those lines, and she saw that he understood more than she had told him. His mouth moved, silently for a moment, and then he said, "The people within the cities; and the army there marching. They will be part of it."

And then he moved around the circular room in excitement. She followed him, over scorched flower-beds and then whole ones; under trailing willows and heavy sprays of flowers. He stopped, suddenly, so that Grace nearly bumped into him, and then he turned to give her a dazzling smile quite unlike his usual smirk.

"A clock, Grace. It's a huge, living clock. Look." He pointed out to where there was another army of men marching across the snow, this one hurrying northwards. "They're marching from Eled Aden and going towards Mida; the midnight city."

Grace trained her eyes on them, and saw that the army was composed of archers and men and women with axes, their clothing tan and black and hardy. She looked onwards to Mida – a vast city that stood at the north of the kingdom, spanning the great river with fantastical bridges and towers, and beyond it she saw that another army of the cold stood poised to fall on it.

"Two armies," she said, sick with momentary fear and doubt. Could any spell be powerful enough to drive them away?

But Ruidic seemed exultant. "Yes, two. The hands of a clock, Grace. They move; and they live. And they will go on moving and living and in their actions will be the kingdom's salvation."

His lips moved again, and he hurried onwards around the garden, following the dome of crystal and looking out at the twelve cities around the wall.

"Turning... Shielding... Summoning... Conjuring..."

He stopped as they completed the circuit, and then seemed troubled for a moment.

"I can see how it will be, every part of it – except how I can join it. A living spell fragmented over miles and joining hundreds of thousands of people..."

He looked at her, trying to read her face. "I think you know the answer to this, too."

For a moment, Grace felt sheer panic rush through her. She had told him the answer, hadn't she? Was there more to it than the living spell? She didn't know how to link spells together.

You have already seen, the book had told her, and it had sent her up here to understand. Was the answer to this here too?

She looked back out at the kingdom, casting her eyes over it frantically without really knowing what she was looking for. A way of linking all these parts, when the only thing these cities shared was that they were enclosed together –

She drew in a breath. "The wall," she said.

Ruidic opened his mouth to ask her more, but she held up her hand while words from the book rushed through her mind.

Tower and wall were built together, cut from the same stone... Where an item has been created out of a substance, it becomes irrevocably linked to every other item fashioned out of that same material...

"It's built from the same stone as the tower," she said, and looked around to find some of the stone here. "So they're resonant substances. If you cast a spell on part of that stone, you can cast it on all of it."

She moved through the garden, realising with increasing frustration that there was no stone here; only plants and earth and the dome of crystal.

"Grace, I've never cast a spell like that before," Ruidic said, as he followed her.

Come on! She thought. There must be some stone here. We don't have time to go and chip some out of the walls.

In a vivid flash of memory, she saw herself hanging outside the tower, while the wall crumbled in her hands. She had been showered with pieces of stone.

She reached up to her hair, and picked through it, laughing as she found a fragment of the grey-white stone of the tower.

"Here," she said, and she lifted Ruidic's hand to place it on his palm. "It doesn't matter how small it is, does it?"

"Grace," he said again. "I don't know how to do this part of it." His exultant self-confidence had faded, and she recognised all too well the fear on his face. It was that same weight of responsibility she had felt since she had arrived here, and the doubt of ever being able to live up to it.

Grace looked at him again, taking in those stormy eyes that saw through enchantment and understood power. They even saw snatches of the future. And watching him, she remembered the power that had struck at her when he was angry, and how much had poured out of him into the shield. She remembered, too, that he had always been the one to see the possibility in others and to judge their strength. Nobody had ever looked on him and judged him. Nobody had looked at Ruidic, who she understood now was stronger than all of them, even Ma and the Queen.

"You may not be Cartheno, but you're strong enough to do everything he did. You've just never had anyone to tell you that."

She saw how the words affected him. How the dazzling showman in him drank them up and satisfied itself on them; but how the half of him that cherished life and loved Ma and wanted to help them all was humbled.

She looked at the tiny piece of stone in his hand. "If you look at it, can you see what you need to do? I think you can."

His eyes travelled down to the slightly glittering stone, and then they glowed again in the way she had come to recognise. He frowned, concentrating.

Grace wondered, with a strange feeling of envy, what he could see. There was so much that his strange eyes could reveal to him, and so much more that he could do than she would ever be able to match.

At last he smiled.

"I couldn't see at first," he said, "and then I drew my whole mind into it, became part of it. And suddenly I could feel everything that was ever crafted out of this stone. I could feel the tower, and the wall, and there are buildings in every city too. Bridges and towers and houses. Even statues and streets."

"So you can do it?" she whispered.

Ruidic nodded, and looked up towards Naian. She wondered if he could see the army reaching the foot of the wall, and how quickly he could cast this spell.

"Yes. I know each symbol of the cities now, except... What symbol is it here?" he asked, quietly, as he pressed his face up to the glass and peered down at the streets.

"Wholeness," she said, pointing to the edge of a rounded-off triangle within the city streets.

He followed her hand, and then looked at the great jagged path of destruction that the cold mage's army had made.

"It's part of it," he said, with a strange note of emotion in his voice. "The damage they wrought on the city is part of the symbol. The mage came, and he finished the symbol without ever knowing what he did."

It was a strange and dizzying thought. But any further thought was cut off by the sudden boom of the mage's voice in her head.

Knock, knock, it said.

And then there were two echoing booms that shook the tower and startled three birds from the branches of a burned tree, their colourful wings flashing as they darted away in alarm.

"Start the spell!" Grace said, urgently. "He's coming."

She turned towards the intention wind disc and began running towards it, wondering if she could shut it off somehow to give Ruidic the time he needed to cast the spell. Burned branches whipped at her face, and she gasped as one of them scraped across the raw, torn skin of her left arm, but she kept on running.

She came into sight of the disc, and then she was knocked backwards. She felt her leg twist under her with blinding pain and then she felt a huge, crushing pressure on her chest. It ground her into the earth of the garden, and she would have screamed if she could have drawn any breath. But she could neither breathe nor move, and her eyes couldn't make sense of what was crushing her.

She tried to push it away, until her hands hit two unyielding leather boots and she realised that the mage was standing with one foot on her shoulder and one on her stomach. He was crushing the life out of her, and she wasn't strong enough to move him.

Possibility, she thought, and in desperation conjured a burst of fire that she threw out from her chest.

The pressure immediately left her as the mage was blasted upwards. The fire was as uncontrolled as it had been when she cast it at the queen, and as she heaved and gasped to draw air into her lungs, she saw it blaze outwards, blotting out the spire above and then, as it hit the crystal dome, curving downwards towards the plants at the edge of the garden.

She knew she needed to see where the mage had gone, certain that the fire hadn't killed him any more than it had the Queen, but there was pain lancing through her with every breath.

Broken ribs, she thought, remembering what they'd been told to look out for in kickboxing. She knew they could puncture a lung if she wasn't careful, and then breathing would no longer be painful - it would be impossible. 

She rolled over and tried to get her feet under her, but her right leg didn't seem to be under her control. When she finally got her toes onto the ground and tried to press upwards, swearing at the pain in her lungs, another fiery line of pain ran up from her leg, and it collapsed.

She wanted to sob. She had to find the mage and keep Ruidic safe. Finishing the spell was everything, but she could barely move.

She started to push herself forwards with her left leg, dragging her right, and clawing along the grass with her hands. She felt dizzy from lack of air, and sick from the pain, but she had to find him.

She flinched as a something stung at her skin, and then the pain came again and again. She realised that it was molten crystal from the dome falling on her, the result of her uncontrolled spell.

A reverberating crack sounded from somewhere overhead, and Grace froze. Twisting her head to peer upwards, she saw that the fire had cleared now, but that the dome was raining crystal down, great gaps opening up in it where it had melted.

And as she knelt there and watched, the huge, glittering spire above her head twisted, and buckled, and began to fall.