He took out his phone. There was a torch on it. He’d never used it before. The grass in front of him lit up, a nasty blue-grey colour.

‘Good thinking, Batman,’ Rita said, as she did the same. ‘Come on, it can’t be far. She must have seen it from the road.’

The three of them spread out and walked down the slope, the expanse of black now animated by dancing pools of hard metallic light. In the sky behind them the sound of a helicopter could be heard in waves that came and went on the wind.

‘There!’ Joe said.

He was already running, phone held out in front of him. In the corner of the field was a small, rectangular building, no bigger than a garage, and a little lower.

They sprinted towards to it, shouting Kieron’s name. The sound filled the valley, massive blasts of human urgency echoing in the darkness.

Joe got there first. It was an old building, no windows on the side that faced him, but neatly maintained. The door was old, but the Yale lock, though tarnished, was clearly not as old. He yanked at the handle, screaming Kieron’s name. The door was locked.

‘Kieron!’ Rita cried as she and Gwyn arrived. ‘We’re here! Police!’

They pulled at the door, all three of them now bawling as loud as they could, but it hardly moved at all.

‘Stand back,’ Gwyn said.

He took a short run and rammed into it with his shoulder. The door and frame seemed to move. But not enough.

‘Take it in turns,’ he said, as he gave it another go.

Joe followed, crashing into it so hard that the pain of the impact shot across his back and down his spine. Then Rita began slamming her foot into the middle of the door. It shifted a little more with each kick, dust and bits of darkened, hundred-year-old mortar dropping to the ground.

‘The whole frame,’ Joe said. ‘Pull the whole frame out.’

He dug his fingers into the old mortar around the bricks, scraping at it with his nails, breathing in the dust until he almost choked, as if he was inhaling clouds of pepper. Finally he managed to get his hand around a whole brick. He worked it loose and pulled it out.

Still shouting Kieron’s name, Rita and Gwyn were now dislodging more bricks, the three of them crowding around the door, shoulder to shoulder, their faces covered in dark-grey mortar dust as they all tried desperately to get a hand around the frame.

‘Come on,’ Gwyn shouted, ‘we’re nearly there. We’re getting it.’

Then there was a noise. They stopped, stood back, as the door opened slowly from the inside.

Two boys were there, each one with an ice-cream cone in his hand.