The fist-sized rock compresses a fraction under the weight of the young boy's step. The shift in its turquoise-tinted shape is imperceptible to a human eye, and yet sufficient to avoid damaging his bare foot. Its ability to absorb the pressure from any passer-by who happens to step on it means that in the many years that it's been there nobody has ever stopped to investigate the source of the fleeting feeling beneath their feet. Which is just as well because it can react, but it has limited ability to move of its own accord. That's why it chose to hide in the tall grass through which the boy was running, to keep itself protected from prying eyes.

Two women approach, and the younger one calls out, "Nigel. Come here."

The boy halts and swivels his head to the side, to face away from her. He hesitates and then lets his head hang loose, chin on chest. Slowly, he turns and saunters towards her with his arms hanging loose, swaying in time with his walk. The rock rolls alongside him, continuing its concealment with the help of the grass camouflage. As they get close, the older woman is speaking. "Whyever did you call him Nigel? Nobody is called Nigel. You've condemned him to a lifetime of ridicule."

"It's unusual," says the younger woman. "And, I'm his mother, not you."

"Alora, I am his grandmother. Your mother. You should listen to me."

The boy's mother coughs, followed by an overemphasised splutter. "You named me Alora, and there are six of us in my friendship group alone. A different kind of ridicule. And, I like Nigel. It's retro and quirky."

The boy stands upright, making it clear he's waiting for his mother to tell him what she wants. Although in reality, he knows it's time for him to take his medication.

"Nigel. Open wide. Let the goodness in," she says with a line so well practised that its pretence of choice is almost believable.

He does as she says, and in the long grass next to him the rock splits its surface and opens a crack to the core of its form. The rejuvenating sunlight pours in, giving it the energy to use the nearby water and soil-nutrients to further boost its power.

"Nigel, clean yourself up," says his mother, and he takes a handful of cleaning agent from his gran and smears it across his hands and face. Meanwhile, the rock disperses itself into a cloud of dust, each particle spinning at tremendous speed to free themselves of any unwanted dirt that's taken up residence over the past few idle years.

The women glance at one another and Alora smiles at her mother. "Nigel, go and play. Explore, as much as you want. Not beyond the edges of the tall grass. Stay out of the trees and away from the beach. For now."

Full of his medication, the boy shoots off as fast as his legs will take him, circling his arms around and around like a wind turbine in high winds. With grass up to his knees, he swishes and swirls his way through the dense growth. Shouting and screaming with joy, he zig-zags across the field towards the trees, the boundary. The reformed rock heads off in the opposite direction. Not attempting to hide itself, fleeting flashes of turquoise give away its location, sometimes above the green tips, sometimes in amongst the blades and sometimes along the ground. Two paths of differing but equally random routes appear in the crumpled grass.

The boy reaches the trees and squats down. Only his head can be seen. He shouts a series of noises, imitating an extinct woodland animal that he learnt about a few days ago. It's a perfect replica. He waits in silence as if he's expecting a response. None comes. The rock reaches its own boundary and forms itself into a bowl shape, on its side as if it's a satellite dish listening for signals. Both of them are contentedly interacting with the woods in their own way, oblivious to each other and yet tied together by Alora's request to explore.

"Nigel," she shouts. "Come back here, where I can see you."

The grass ripples as he runs back to her. On the other side of the field there's a faint flutter in the tips of the grass as the rock also returns to the two women, coming up behind them while they focus on the boy's progress. The boy bursts into the small clearing where the grass has been cut back and they are waiting. A few moments later the rock rolls in and circles around their ankles until it too is in their sightline.

"What the-?" says the boy's grandmother. "Wow, it's a Nanodust Nigel."

"A what?" says his mother.

"A Nanodust Nigel. I'd forgotten they existed. A kitchen gadget. In its dormant state, it was this beautiful turquoise rock, an object to be admired. Made of nanodust, you could tell it what to become, what to do. It could form any kitchen implement you desired. Knife, chopping board, cloth, saucepan, and so on. Wow. That's amazing, to see one again."

"Did you call it Nigel?"

"Yeah. It needed a name that had gone out of use, otherwise you'd trigger it accidentally, and the name for home AIs already in use-Alexa at that time-was being widely used for real girls." The grandmother kneels down to take a closer look. "I never thought I'd see one of these again. They got a bad reputation for 'missing the point' and were destroyed for being dangerous, every single one was decommissioned."

The boy steps forward and gently nudges the rock with his big toe. He pushes it forward a few centimetres and then rolls it back with the ball of his foot. He tries to squeeze it between his tiny hands and when that fails, he picks up a sharp stick.

"Don't do that," says his grandmother.

He pokes the rock with the stick, ignoring her warning.

"No," she shouts, "they protect themselves."

Almost as if it heard her, the rock releases a fine spray that stings the boy, who quickly withdraws his hand, screaming in pain.

"Nigel," shouts his mother. "It attacked you." She looks at his grandmother. "Terminate the bloody thing," she screams.

His grandmother shouts back, "No, you stupid-"

It's too late. With that command, Nanodust Nigel forms into a flexible clothlike sheet, lifts off the ground and wraps itself around the boy's face, covering his mouth and nose. Mother and grandmother leap to the boy's defence, attempting to prise the nanodust cloth off him. Muffled screams fill the air as it stuffs itself into his orifices and chokes him. His mother pulls and pulls at the cloth, shouting, "Nigel. Get off. Leave him alone. Stop."

The nanodust ignores them; first it must pursue its instruction through to its conclusion, to kill that which had attacked it.