Joe peered closer. They had moments left before the stream spilled its banks. It was still bubbling up from its underground source, super-heated like a geyser, from the volcanic jets deep below the island.

Ren and Fidell hopped down, leaning over the water.

‘Wait,’ Joe said, watching their dragons.

‘Careful!’ Winter said. ‘It’s hot.’

Joe could feel the heat rising from the stream. But Ren wasn’t careful. She dived straight in, splashing them. Joe jumped back as the water hit him, scalding hot. ‘No! Ren!’ he yelled. He stared down at the water, unable to follow. ‘What’s she doing? Come back!’

Winter put one hand on his arm. ‘Wait – look! She’s swimming. She’s fine.’

Fidell dipped his nose in, looking below the surface, then he too glided in smoothly, barely rippling the surface.

‘How can they bear it? Why aren’t they hurt?’

‘They’re shadow dragons, aren’t they?’ Winter said, grow­ing excited now. ‘Born from four elements: they can do this. They’re trying to help.’ She brought her face close to the water, muttering softly, ‘Go on, Fidell. Go see what’s happened.’

Both shadow dragons swam away, sleek as otters, vanish­ing under the water.

Joe and Winter waited, eyes on the bubbling stream, getting higher and higher every moment.

Moments passed. Joe held the storm lantern over the water and paced up and down. The water trembled on 308the lip of the channel, and then poured over its edge, splash­ing onto the floor.

The people of Arcosi were still clambering out of the way, but the dragonriders and the duke’s soldiers had gathered each neighbourhood again, and there seemed to be order within the chaos, as they moved higher in turn and started filing into the tunnels.

But there was one problem. The fully grown dragons couldn’t enter the upper tunnels – they were too large – and the rising hot water now blocked the main entrance from the beach. The adult dragons were stuck here, till they could leave the way they’d come in.

‘Joe!’ Amina called from the other side of the cavern. ‘Come on, you two! We can’t leave without you.’

Tarya and Vigo, Milla and Thom, Isak, Rosa and all the other dragonriders waited with their dragons at the far side of the large cavern, watching them intently.

‘We can’t!’ Joe shouted, feeling the heat of the water through the leather of his shoes. ‘We can’t leave Ren and Fidell.’ He didn’t need to ask Winter – he knew she felt the same.

‘No! Save yourself, Joe, please!’ His mother huddled on the top step, refusing to leave, though Conor and Amina were there, begging her to move to safety.

‘Mum, I’m sorry. I can’t.’ Joe kept his eyes on the place where he’d last seen Ren. There was a tight knot in his stomach. All the people he loved most in the world were here, climbing the stone steps up to safety, or watching the waters rise. 309

He waited for Ren. He had faith in her. He did. But he was being eaten up by desperate fear. Surely it had been too long?