Rule One

Priya didn't sleep. She sat on the lid of the chest freezer with her knees up inside her hoodie, a small grey tent with a head, and watched him.

Dev sat on an upturned bread crate by the gap with the pallet bar across his thighs. The freezer under her hummed. Outside, the wind worried at the car park and found every loose thing in it.

"What does yours say?" she asked.

"My what?"

"Your window. Don't do the face. Everyone's got one. Mine says occupant. Yours says something better."

He thought about lying. The price gun was in his hoodie pocket, and his thumb found the trigger and squeezed it twice before he noticed.

"Keeper," he said. "Level one."

"Points?"

"One."

She did the eye thing, reading the air, though there was nothing in front of her. She was reading him.

"One," she said. "And she was here last night. And I wasn't." The cord went into her mouth. "So it's per head. Per night. Probably at dawn, because that's when you'd know nobody got eaten." She chewed. "Tonight you're on two."

He said nothing. She took that as a yes, because it was.

"What do you buy with it?"

"I haven't bought anything."

"Saving up." She nodded slowly, like a bank manager who had expected no better. "What for?"

Outside, something went ting.

It was a small, bright, stupid sound. A bicycle bell, nudged by the wind where the bike lay twisted against the line. Out in the dark, claws scraped on tarmac, and a ridged shape came walking out of the gloom with its head low.

It stopped at the blue line. It breathed its clicking breath at the bike. Then it stood there.

A second one came. Then a third.

Ting.

"Brilliant," Priya said. "I've built a doorbell."

The three of them stood at the threshold, a yard from Dev's trainers, heads tilting at each gust. When the wind dropped, they wandered a few paces off, and when it rose again they came back. The fourth time, one of them stayed and lay down, chin on the line, like a dog waiting for a shop to open.

"They'll keep coming as long as that thing rings," Priya said. She slid off the freezer. "I'll go and kill it. Two seconds. I'm small."

"You're not going out there."

"I'm not asking. I'm telling you what's happening."

"Then I'll go."

She looked at him the way she'd looked at the loading screen of the two of them earlier. "You've got a sixty-second leash and a nosebleed. I watched you this afternoon through a hedge. You looked like a dropped puppet."

He hadn't known anyone had been watching. He went to wake Margaret.

She was on the dog beds in the pet aisle, on her back, hands folded on her chest like a stone knight. She woke the instant he said her name and looked at the watch before she looked at him.

He explained. She sat up, put her wellies on, and came to see for herself, and the three ridged things at the line watched her come.

"No," she said.

"I haven't said anything yet."

"You were going to say it's short. Twenty seconds. Ten." She tightened the cord of her dressing gown. "A bell is not a reason. A bell is a nuisance."

"It's bringing them to the door."

"They can't come in the door. That's rather the point of the door." She looked at Priya. "And you're not going either, so don't."

Priya's eyebrows went up, very slowly.

Dev looked at the bike. Front wheel buckled, handlebars twisted toward the gap, the bell on the left grip. The front wheel was nearest, barely two feet past the line.

He lay down.

The lino was cold through his hoodie. He lay flat with his chin an inch behind the blue light, close enough to smell the creatures, wet dog and something like hot pennies. The one with its chin on the line opened an eye at him. It had a lot of eye.

"Devon," Margaret said.

"I'm inside. Every bit of me." He slid the pallet bar out along the tarmac, flattened hook first. "The bar isn't me."

No countdown. Good. He'd half expected one.

He hooked the front wheel. The steel scraped. All three heads came round to the scrape and the one lying down got up, and they stood over the bar, breathing on it, while he drew it back inch by inch. The bike came with it, grinding and complaining.

"You're making it worse," Priya said, but she was on her knees beside him.

"Short term."

The handlebar crossed the line. The creatures pressed against the light as if it were glass. Priya reached past his shoulder, gripped the bell, and twisted it off its clamp with a crunch of cheap plastic.

The car park went quiet. Without the bell, the bike was just a bike. One by one, the creatures lost interest and drifted away to wherever they went when nothing rang.

Priya sat back on her heels with the bell in her palm. She flicked the lever with a fingertip, very softly, so it barely made a sound. Then she put it in her hoodie pocket.

"Souvenir," she said.

Dev rolled onto his back and looked at the dead ceiling lights. His chest still ached from the afternoon, a deep dull thumb pressing from the inside.

A window appeared above his face.

[Occupancy: 2. Keeper may set Zone Rule 1. Rules are binding. At Level 1, Rules cannot be revoked.]

He read it twice. Then he read it out loud, because he could feel Priya watching him read.

"Cannot be revoked," Margaret said. "Not ever?"

"Not at level one."

"Then you think very carefully," she said, "and you say no weapons."

"Bit broad," Priya said.

"No blades, then. Not under this roof. I've stitched enough people who carried a knife to feel safe."

Priya didn't answer. She held out her right arm and shook it once, and a craft knife slid out of her sleeve into her hand. Yellow plastic, a snapped-down blade, the kind Dev used for cutting shrink wrap off pallets. She didn't point it at anyone. She just held it, so they could see it was there.

"I walked over a weir in the dark," she said. "I'm not giving this to a man who gets paid when I'm unconscious."

"Nobody's asking you to give it to him," Margaret said. "I'm asking you to give it to me."

"Same building."

Margaret's mouth went thin. She turned the crown of her watch, one click, and didn't wind it.

"Make a rule against her, then," Priya said to Dev. "Go on. You've got one shot and it can't be undone. Rule One: the girl's not allowed to keep the thing that makes her not scared. Very safe-zone."

"I'm not making a rule against you."

"Then make one for the bank." She tilted the knife at the ceiling, at the invisible air where his window was. "Something that keeps your deposits nice and quiet."

He sat up. His glasses had stayed on his head, for once. He pushed them up further, out of habit.

He thought of last night. Margaret asleep with her hands folded, and him on the crate, and the knowledge that if somebody came through the gap with bad ideas, the only thing between them and her was a tired man with a bar he didn't know how to swing.

The Zone didn't stop people. Only monsters.

"Nobody harms anyone who is sleeping," he said.

He said it to the window first and then, because it felt wrong to say it only to the air, he looked at each of them and said it again.

The words went out of him and the hum from aisle seven changed note. Under his feet, through the soles of his trainers, he felt it settle into the floor, like a tile pressed home into wet grout.

[Rule 1 set: Nobody harms anyone who is sleeping. Offenders will be ejected.]

Margaret let out a slow breath through her nose. "That's a decent rule."

Priya was looking at him with her head on one side.

"That's a decent rule for you," she said. "Sleepers are what you get paid for. That rule protects your money."

"Yes," Dev said.

She waited for the rest of it. The but. The speech about how he wasn't like that.

"It does," he said. "It protects the thing that pays me. It also protects you when you're asleep, and Matron, and whoever comes next. I can't make it only do the nice half."

Priya chewed the cord. The freezer hummed. Somewhere out in the dark, the wind found a drinks can and lost it again.

Then she clicked the blade back into the handle and slid the knife into her sleeve. Not into Margaret's hand. Into her sleeve.

"Fine," she said.

Margaret watched the sleeve. "That rule says sleeping," she said quietly. "It doesn't say anything about awake."

"Then stay awake," Priya said. "I am."

Margaret looked at Dev as if he had left something off a shopping list. He had. He knew it. It was done.

Priya pulled her knees back up. She seemed smaller with the knife put away, not larger.

"You want to know about the torch," she said. "You've been wanting to since I said it. You keep looking at the back wall like you can see through it."

"Can you show me?"

"From here? No." She thought about it. "There's a ladder in your stockroom. Goes up to a hatch. I saw it when I was having a nose round earlier. Flat roof, yeah? You'd see over the bus garage. Straight across."

"What do you want for it?"

It surprised him how easily it came out. It surprised her too. The cord stopped.

"When you buy something," she said. "With us. I want to see the list first. All of it. What it costs and what you're picking."

"Done."

"And you don't call me love."

"I never have."

"I'm saying it in advance."

The stockroom smelled of cardboard and cold. The ladder was bolted to the back wall beside the cages of toilet roll, steel rungs painted yellow, rising to a square hatch with a lever handle. Dev had walked past it for four years and never once climbed it. Roofs were for maintenance, and maintenance was for days.

He went up. Five rungs, six. The ache in his chest woke and complained about it. At the top he set his shoulder against the hatch, turned the lever, and pushed.

Cold air came down on his face. Stars, more than he'd ever seen above the city.

And a hook in his chest.

[Beyond threshold. 00:60]

He froze with his head and shoulders in the night. The roof was gravel and puddles and a dead air-conditioning unit the size of a car, and it did not belong to him. The Zone stopped at the ceiling.

"Devon." Margaret's voice came from below. Not loud. "Down."

"It's the roof," he said. "It's outside. It counts."

"Then come down."

00:54.

He looked down past his own knees. She was at the foot of the ladder with the watch already up, and Priya behind her with her arms folded, and the countdown burning in the corner of his eye.

"I need to know if it's him," he said. "I'm not running. I'm not going anywhere. I just need to see."

Margaret looked at him for one second of the fifty-one he had left. Then she put a welly on the bottom rung and climbed two rungs, so her face was level with his ankles and she could see the watch and him together.

"Fifty," she said. "Go on, then."

He pulled himself up so his elbows were on the gravel. The hook dug in at once, a fist closing. The world leaned slightly to the left.

[Bond strain. Recovery incomplete.]

The same window as in the car park. Yesterday had not finished with him, and the countdown was not going to wait for it.

"Forty-six."

There. Past the bus garage, past the black gap where the river must be, the flats on Halsey Street stood up against the stars like a shoebox somebody had stood on its end. No lights anywhere. Every window dead.

Except one. Third floor, near the right-hand end.

"Forty-one."

A torch. Small, yellow, too far to be anything but a point. It wasn't pacing.

It went on and off. On and off. On and off.

Then dark.

"Thirty-seven."

On and off, three times. Then dark.

His hands had gone cold on the gravel. He knew it before he could have explained it. Their kitchen on Ashby Road, the strip light over the cooker, and Mum standing at the switch when it got dark and the two of them were still out on the green with a football. Three flicks, a gap, three flicks. In. Now. Both of you. Kayode used to pretend he hadn't seen it. Dev always went in first.

Nobody else had ever known what it meant. Nobody else had been there.

"Thirty-two," Margaret said, steady as a drip. "Devon. Thirty-one."

Across the river, in the dark, the light flicked three times again.