They stopped at the juncture of two grassy footpaths. A large oak tree shaded them; the hedgerows were alive with birdsong. In a field beyond, a red kite swooped. Somewhere far distant were the noises of car engines.

Kit looked through the glass and grunted. Then he said, ‘Close your eyes an’ take my hand.’

Tom folded his arms.

‘Do as I say.’

Shrugging, Tom took Kit’s right hand and closed his eyes.

Kit murmured some words in a language that Tom didn’t understand.

‘Go to it. Say it wi’ me.’

‘What are we doing? Is this some kind of game?’

‘Just do it.’

Kit was clutching the chain, his knuckles whitening. There was something both pleading and commanding in his tone. Well, thought Tom, what’s the worst that can happen? Tom repeated the syllables, not understanding them.

Suddenly, once more, he felt as if reality were sliding away from him. The solid world began to shiver, and he wondered briefly if he had been drugged that morning. He glanced at Kit, but Kit was still muttering the words, eyes tightly shut.

Tom closed his eyes. Now he saw a shimmering wall of light and energy enclosing the entire farmlands. It was astonishing. Power was crackling off it. The words, he saw, were taking on power and life of their own, weaving into the walls, and feeding into them.

He felt a spasm in his stomach, and watched his own power flow out, in a river of light, and falter, and then come up against something that sent it curling back to him. It hit him with a punch.

‘Folk been there,’ said Kit. ‘Hold steady.’

He tried again; and this time, Tom realised he could avoid the obstruction, and weave round it. Now he could not stop saying the words, could not break what he was doing, knowing that if he did, he would end something vital. He explored along the length of the wall. At various points it was weak, as if animals had been making inroads into it, and at other points it was thick and strong. The words were bound up with the wall, and fed themselves into the scheme of it.

Kit kept repeating the words, harsh syllables with deep meanings Tom could almost grasp, and Tom followed him, getting stronger and stronger, until he and Kit were evenly matched. As their voices joined together, there was a sudden burst of light and the whole wall glowed with renewed energy.

Then Tom had to let Kit’s hand drop. He gasped, opening his eyes. Someone was walking their dog a few fields away. A bee was lazily hovering near his nose. He stumbled, grasping onto a tree trunk for support. Kit regarded him with an unreadable expression.

‘What happened?’ said Tom, when he had recovered.

‘Master was right. You don’ need no training.’ He spoke thickly, and Tom couldn’t tell if he was praising him or damning him.