Joe held up the clam-shell light, carefully so he didn’t spill the oil. He studied the master map carved into the cave 79wall. The cavern where they stood looked like the heart of the island, and these tunnels were its veins.

‘Let’s go west,’ he suggested. ‘This branch here.’ He pointed, tracing the groove with his fingertips. The burns were all healed up now, though his shoulder still ached where he’d fallen, and he could feel his hair growing back in curly tufts where it had been scorched. ‘I feel like there’s more to find over here. See this tunnel above it? That goes right to the shadow strip.’ He pointed to the ruined neighbourhood in the far north-west of the island. ‘So maybe this one has an interesting end too. Do we have enough parchment?’

‘Sure,’ Winter said. ‘I can draw on the back of this.’ She smoothed out the section they’d used the day before.

‘Why do the tunnels only cover the west side of the island, not the east?’ Joe asked, without looking round, fingers tracing the whole network now. He’d discovered that they had secret entrances in many different neighbourhoods, including one near the Yellow House, his old home. His heart lurched as ever at the thought of his parents, but he focused on the lines in the rock, determined to stay strong. It was better for everyone this way.

‘Everyone forgot the tunnels,’ she shrugged. ‘They forgot the reason for them too.’

‘I wonder if they knew about them in my great-grandmother’s day, when the dragons almost died out? They had to abandon the island. Maybe the knowledge of the tunnels went with them too?’ Joe’s great-grandparents Karys Stormrider and Gallus Dorato had fled the violence of mad Duke Rufus, along with the only remaining dragons, Cato 80and Aelia. Aelia laid four dragon eggs, the ones Iggie and his nest-mates had hatched from more than fifty years later.

‘I did go to school too, you know,’ Winter teased him. ‘If I recall, we never stopped hearing about your brother Isak who set the school up.’

‘I know! Imagine what it’s like being his little brother,’ Joe said dryly, gesturing for her to carry on and trying to ignore the pang he felt at the thought of Isak, who would now believe he was dead.

‘So when the Norlanders came, they didn’t know about the tunnels,’ Winter continued. ‘That knowledge had gone with Karys’s people and the dragons.’

Joe nodded thoughtfully. His father’s people had arrived, fleeing famine and hardship in their homelands. ‘The Norlanders moved in, with no idea what was under their feet,’ he said slowly. ‘And as sea-people, perhaps their focus was on the shores, on the seas, not under the ground. None of us knew, all this time …’

‘Till now,’ Winter said.

‘Till us.’ Joe smiled at her. There must be secrets down here! Something worth finding. He felt it like a little flame inside, keeping him going.

Later that night, while Winter’s breathing turned deep and soft in sleep, Joe lay awake thinking about the lost past. Maybe the tunnels had helped Karys escape the island, back then. He liked the idea of retracing his ancestor’s steps. He might be cut off from his living family, but it comforted him to feel connected to Karys Stormrider, so long ago. She was a survivor, and he would be too. 81