Imagine a classroom in a primary school in the south of England, in the closing years of the 20th century. It’s lunchbreak. The ten little pupils who attend the special class for children with speech and language difficulties are out in the playground. Nine of them are racing about and playing. The tenth has something more pressing to do. He is standing at a distance, partially camouflaged by some bushes, watching the classroom door with close attention.

Inside the room, his teacher is ensuring that everything is ready for the science activity she has planned for the afternoon’s lesson. Carefully she lays out all the materials the children will need for an open-ended exploration of magnetism. Once she’s satisfied that everything is in place, she leaves the classroom and heads for the staffroom, to eat her lunch and chat with colleagues.

This is noted by the six-year-old who has been watching. Now, he must act fast. He has planned his course of action meticulously. Entering the school is not permitted at lunchtime. He knows that. However, he has purposely left his coat hanging on a peg inside the room. If challenged, he can tell the dinner lady he’s cold and needs his jacket. The midday assistants find children from the special class difficult to understand, so avoid interacting with them too much. The child knows they’re unlikely to bother with him.

Rubbing his shoulders convincingly, to indicate the effect of the biting east wind to anyone who may notice him, he opens the door.

Once inside, it takes him seconds to observe his teacher’s preparations. Keeping low, so as not to be spotted through the window, he selects a large magnet from the centre of her table and deposits it at the bottom of a plastic box of crayons across the room. He then takes his coat from its hook and heads back outside.

“What you up to, Asher?” calls a dinner lady.

“I det my doat. I wah dold,” he says, wrapping his arms around himself to help her understand.

She nods and turns away. The first half of his mission is successfully accomplished.

At the start of the lesson, as all the children sit expectantly on the floor in front of her, Mrs Kerzen looks concerned.

“Oh,” she says. “That’s odd. I was sure I had everything ready for science. Can anyone see a big magnet? Has it fallen on the floor somewhere?”

Those who have understood start to peer around or shuffle about.

“Wut do it loot lite?” asks Asher, in his most helpful way.

“What a very sensible question, Asher,” his teacher smiles. “It’s about this big and shaped like a horseshoe. It’s red, with silver at the ends. Like this.”

She draws a quick sketch on the whiteboard. Now everyone understands. A full-scale treasure hunt follows. Children are on their feet, looking in every corner of the room. Asher knows he must be quick. It’s imperative that he is the one to find it. Appearing to search convincingly as he moves across the room, he reaches the crayon pot before anyone else. Slowly and carefully, he roots through the contents. With a perfect impression of surprise, he pulls out the missing object.

“Are dis it?” he asks, holding it aloft.

“Good gracious! Yes, Asher, it is. Thank you. How on earth did it end up right over there?”

“It wah in de drayon bods,” he says, levelly, as he hands the magnet over.

For a fraction of a second, the teacher looks curiously at Asher, before continuing with the delayed lesson.

Asher notices that. He’s careful not to let his excitement show, but he feels hopeful.

For years, now, he’s been trying out little tests like this on various adults in his life. All have been depressingly easy to fool. He needs to find the one who is sharp enough to notice. He gives just enough clues, but not too many. The right person will realise what he’s doing. That person will challenge him. Then he will know he’s found the individual he’s been hunting for; the one who agreed to work with him in that deal he clearly remembers making before he was born into this lifetime.

Not long now.

It will be Mrs Kerzen, his teacher, who spots what he’s doing. He’s almost certain of it.

If you have read A Mind Beyond Words, you’ll know about some of the other ‘tests’ Ash used, to make sure I was up to the job he had planned for me.