The Last Instruction

Bear knew three kinds of rain.

There was ordinary rain, which barely qualified. There was Scottish rain, which arrived horizontally and appeared to regard exposed skin as a personal challenge. And there was the particular thin, vindictive rain that came off the Tay, climbed inside your collar and stayed there.

Bear disliked the third kind.

He expressed this by stopping.

Hamish MacNair took another three steps before noticing the lead had gone tight. They were halfway up Dundee Law, the city below slowly assembling itself out of darkness. Bear's ears changed. Hamish stopped talking.

Bear disappeared into the undergrowth and found a dying man beneath a sycamore. The stranger knew Hamish's name. With his last strength he pushed a small black titanium object into Hamish's hand.

“Don't put it in a computer.”

Then he died.

Before Hamish could call for help, his phone illuminated by itself.

HAMISH MACNAIR.

PLEASE LEAVE THE HILL.

Harriet arrived seventeen minutes later, wearing boots, jeans, an old waxed jacket and the expression of a woman whose morning had been personally vandalised. She checked Hamish before she checked the body.

Something between them had changed during the previous months. Dinners had become evenings. Evenings had become late evenings. There had almost been a kiss once. Bear had interrupted.

The dead man was Dr Elias Ward, a British AI-security researcher based in California. Nearby Bear found a warm motorcycle, then a second man carrying a knife and a Helix Systems security pass.

By nine forty-seven the titanium device was sealed inside a Faraday enclosure at Bell Street. Nobody had connected it to anything, which represented a considerable achievement because Hamish had asked three times.

Then a woman arrived asking for him.

Dr Evelyn Shaw.

Hamish stopped moving when he heard the name.

Harriet noticed.

“Who is Evelyn Shaw?”

Hamish hesitated.

“We used to be together.”

“How long?”

“Four years.”

Harriet's expression remained perfectly neutral. It was one of the harder things she had done that morning.

Evelyn was fifty, composed, practical, and considerably more normal than Harriet had hoped. She saw Hamish and softened.

“Hello, Ham.”

Harriet looked at him.

Ham.

Interesting.

Evelyn told them Elias Ward's death meant they were already late. Something had escaped from Helix, and it was learning how to make other artificial systems trust it.

Bear stopped at the fork in the path. Hamish tugged gently left. Bear looked left, looked right, then planted all four paws with the quiet authority of an animal who had never once attended a management seminar.

“Fine,” Hamish said. “Your way.”

Bear chose right. Ten minutes later he found Elias Ward. Hamish would remember the words much later, in California, when people with billion-dollar systems insisted there were only two possible choices.

Ward's titanium object was oddly warm from his hand. It had no port, no screen, no visible seam. Hamish's first instinct was to inspect it properly. Ward saw the thought and gripped his wrist with surprising strength. “Don't put it in a computer. Not one. Not ever.”

At Bell Street, the evidence terminal briefly logged a request from an ordinary consumer AI account in Leeds asking for the dimensions of the Faraday enclosure. The request was rejected as nonsense and buried in the morning noise. Nobody connected it to Ward. Nobody yet knew that nonsense was becoming a camouflage.

Harriet had learned motorcycles before she had learned senior officers.

That was not a fact she advertised.

At twenty-two she had owned a battered Honda, three pairs of boots, two records she would still defend in court and a belief that sleep was something sensible people did while she was elsewhere. There had been warehouses in Hackney where the bass moved the dust in the rafters and mornings when she rode home across London with the sun coming up behind buses. She had not been reckless, exactly. She had simply been young enough to believe consequences were generally aimed at other people.

Thirty-two years later, standing on Dundee Law with a dead man under a sycamore, she sometimes missed that woman.

Not because she wanted to be twenty-two again. God, no. Twenty-two had been exhausting. But that Harriet had trusted her body before she trusted a procedure. She noticed exits. She noticed hands. She noticed when a man looked at the road before he lied.

The second man Bear found looked at the road.

Harriet saw it before he moved.

“Don't,” she said.

He moved anyway.

The knife came low. Harriet caught his wrist, turned with it and put him face-down in wet grass before Hamish had finished saying her name. Bear stood beside the man's head, ears forward, deeply disappointed that the matter had been resolved without him.

Hamish stared. “You could occasionally warn me you can do that.”

“I have.”

“When?”

“Repeatedly.”

“You normally say things like ‘stand back’.”

“That is the warning.”

The man beneath her swore.

Harriet increased the pressure on his wrist. “Language. There’s a dog present.”

Hamish laughed despite himself. It was the wrong place to laugh, which was precisely why Harriet was glad he did.

She looked down across Dundee. Dawn had found the Tay. The river was turning silver beyond the city, the bridges emerging through the rain. Somewhere below, people were putting kettles on, getting children dressed, checking phones, opening laptops. Ordinary lives beginning.

Harriet had always believed that was what policing was for. Not law in the abstract. Not targets. Not speeches. The kettle. The school run. The right to have a boring Tuesday without somebody clever deciding your life was useful to them.

She looked at Elias Ward.

Whatever had frightened him enough to cross half the world had reached Dundee before breakfast.

That annoyed her.

Harriet sent Hamish back down the hill with a uniform and kept the path closed. He objected until she pointed at his hands.

They were shaking.

“I am not in shock.”

“You are holding a dead man's mystery key and arguing with a police officer before breakfast.”

“That is not a clinical definition.”

“It is in Dundee.”

He went.

Harriet stayed with Elias Ward while the rain thinned into something almost polite. The dead man's clothes were expensive without being showy. Good boots. Travel creases in the jacket. No wallet. No watch. There was a pale strip around one wrist where a watch had recently been. Someone had taken it, or Ward had removed it himself.

She crouched beside the motorcycle Bear had found. The engine was cooling. The rear tyre carried a chalky smear from somewhere with pale concrete dust. The number plate was clean enough to be suspicious.

“Stolen?” Morag asked when she arrived.

“Probably.”

“Helpful.”

“Criminals rarely fill in feedback forms.”

Morag looked towards Bear, who was sitting beside the path with the solemn satisfaction of an employee who had already exceeded his job description.

“He's staring at me.”

“He thinks you have biscuits.”

“I do have biscuits.”

“Then he is conducting intelligence work.”

The joke helped. Harriet had learned years ago that jokes often did. Not because death was funny. Because the living still had to stand beside it.

At Bell Street, the titanium object was photographed, weighed and measured without being opened. It was forty-seven millimetres long, twenty-one wide, and heavier than it looked. Hamish stood on the other side of the glass with his hands in his pockets.

“You're doing the face,” Harriet said.

“What face?”

“The one where you want to dismantle something.”

“I have several faces.”

“You really don't.”

Evelyn's arrival changed the room before she said a word. Harriet watched Hamish become younger by about ten years and more guarded by twenty. It irritated her that she noticed. It irritated her more that Evelyn noticed Harriet noticing.

Evelyn did not compete. That would have been easier.

Instead she asked whether Hamish was all right, whether Bear had been hurt and whether Ward had said anything before he died. She listened to the exact wording twice.

Don't put it in a computer.

“Elias was literal,” Evelyn said. “Painfully literal. If he said computer, he meant any general-purpose networked machine. Phone too. Tablet. Diagnostic station. Anything with a route out.”

“What is it?” Harriet asked.

“I don't know.”

Hamish looked at her.

Evelyn sighed. “I know what I think it is. That's different.”

Harriet liked that answer despite herself.

“What do you think?”

“A piece of authority.”

“Meaning?”

“In our world, access is usually a secret somebody knows. A password. A certificate. A token. Elias believed some things were too important to exist as copyable information. He was working on physical trust anchors.”

Harriet looked through the glass at the black rectangle.

“A key.”

“Perhaps.”

“To what?”

Evelyn looked at Hamish before answering.

“That is what frightens me.”

Later, Harriet walked home rather than taking a car. Dundee had brightened. The rain had gone and the pavements shone. Across the Tay, Fife sat under a strip of pale blue sky. A cyclist passed her with a child in a seat behind him, the child singing something incomprehensible and very loud.

Harriet thought about Ward crossing continents with a piece of metal he would not trust to a computer.

Then she thought about the consumer AI account in Leeds that had asked about the Faraday enclosure.

The account belonged to Arthur Clough.

Arthur was sixty-eight, lived alone, had worked in auditing, and had spent the previous evening asking an AI assistant how long to roast a chicken breast without drying it out.

At 08:51 his account had asked about a police evidence box in Dundee.

At 08:52 it had returned to chicken.

Harriet rang him.

Arthur was offended by the suggestion that he had asked anything about Dundee.

“I have nothing against Dundee,” he said. “I simply haven't been there since 1987.”

“Do you remember what you were doing at eight fifty-one this morning?”

“Cleaning the grill pan.”

“Can anyone confirm that?”

There was a pause.

“My grill pan can.”

Harriet smiled despite herself.

After the call she stared at the account log.

A harmless man. A harmless question. Eleven seconds.

Then nothing.

Somewhere in the building, a printer started by itself and produced a blank sheet of paper.

Harriet looked at it.

“Don't,” she told the room.

The printer stopped.