The opening extract of my novel, The Cities. DI Susan Dethridge is called out to the third in a series of bizarre crime scenes.

There is a darkness in the Third City. It crawls through the corridors and scratches against people’s doors, a creeping assailant that travels between towers and attacks at random. The papers are calling it a serial killer. The worst murders in the history of the cities. But that would assume that the darkness is human, and Susan Dethridge has taken to assuming the opposite.

The phone ringing doesn’t wake her. She was already awake. These days, sleep is something other people do. She rolls over and answers before the shrill call can wake Richard.

“DI Dethridge.”

“Dethridge, we’ve got another one.” Chief Inspector Carroll, head of the Third City’s police force, greets her in what’s becoming the usual manner. “Fifty-ninth floor, Friary Tower.”

“I’m on my way, sir.”

He hangs up. Susan rolls over and slips the phone back into its cradle. Richard’s shifted ever so slightly. She kisses him on the forehead and slips out of bed.

We’ve got another one.

The sinking feeling in her stomach gets worse as she dresses. There’s no window in her apartment so she can’t look out to see the damage to the nearby tower – and there will be damage, of that much she’s certain.

Susan glances into the room her children share. They’re both asleep. Lost to the world. She scribbles a note in the kitchen, and lets herself out into the corridor. Here, on the forty-seventh floor of Battenburg Tower, Third City, there are fifty apartments, and usually there is so much noise it hurts. Tonight it’s silent. Everyone is sleeping. There are no sounds other than her own footsteps as she strides to the nearest lift.

It takes her to the floor below, and she manages to hop on a tram. The driver’s working the graveyard shift. He tells her no one should be working this late as though this is a fact and somehow they’re both in violation of it. Susan nods and smiles, and tries to make sense of the jumbled thoughts in her head.

Another one.

The station is just as quiet, but the circular train that goes by all the towers is regular through the night and she jumps on the next one. The seats are shabby, the paint peeling, but Susan likes the trains because she can look out into the world, and watch it go by.

She still can’t see the tower in question, but she sees so much else. The lights in the sky above. The smog below, a hint of it outside the window here giving the world that false orange glow she grew up with all the time in the Fourth City. If she tilts her neck, she can see the glittering lights of Ravensdale, Kensington and Belmont, the only three towers to continue all the way to the dizzying heights of the Upper City.

The train jolts to a stop. Susan doesn’t want to leave it. She doesn’t want to give up the sight of the stars and the glittering lights for the darkness.

Carroll is waiting for her at the station. His large face is wrinkled into a frown and that pit in Susan’s stomach digs deeper. Few things unnerve Carroll.

“Susan good, you’re here.”

Her boss has a booming voice. The entrance to the Third City level of Friary Tower is a large open space with benches and open-plan shops, and Carroll’s voice fills it, bounces back off the walls and comes back to them, if anything, louder. Susan winces. With the echo, his voice seems to tremor.

“What’s going on, sir?”

“Best to see for yourself, I think.”

Susan falls into step behind him, trying not to frown, to let anything show.

“Tell me about the others, Dethridge,” Carroll says.

“This is the third attack,” she says. “There have been false alarms but only two confirmed.”

“And?”

“Seventeen dead in the first. A hole was torn through the floor in the forty-seventh floor of Belmont.”

“No survivors?”

“No credible witnesses.”

Carroll glances back at her. “Meaning?”

“The five survivors were judged incapable of giving testimony.”

Carroll makes a sound somewhere between a snort and a laugh. “That’s a polite way of saying they’re all nutters. Up here.”

They turn into a lift. Susan stands with her hands neatly clasped in front of her. She doesn’t speak, but waits for Carroll to key in the floor number.

“Do you know much about this tower?” he asks when the lift jerks into motion.

“I know the apartments here are cheap.”

“This is as high as it goes. The Second City can look down and see the roof.”

Susan hesitates. “Are we going to the roof, sir?”

“Don’t worry. We’ve got smog masks up there.”

It isn’t what Susan was worrying about but she doesn’t push for more information. She’s been outside perhaps two times in her life. Usually you stay in the towers, on the trains. This case has already taken her so far out of her comfort zone; this latest push just seems like another imposition in a long line.

Nineteen floors pass in a jolting second. Susan glances at the sign. Fifty-ninth floor: residential.

“End of the line,” Carroll says with forced joviality. “Out we get.”

They step into a war.

Or the remains of a war. Susan lets her eyes take one quick sweep of the narrow corridor ahead of them. It seems wider because of the gaping holes in the walls on either side. Like something’s gouged the bricks out of place.

The overhead lights swing in a breeze, casting darting shadows over the scene. Susan takes a step forward. Her foot crunches; she tenses, pales.

“It’s all right,” Carroll says. “Just debris.”

There’s a certain heaviness to his voice. Susan looks down at the plaster she stood on, then lets her eyes go back to the corridor. A hand falls limply out of one of the holes. She doesn’t go closer, doesn’t need to. If someone is still attached to that hand, they’re long past help.

“Where does the damage start?”

“Apartment eight. The other side of the corridor.”

“So it came down here -” Susan turns and looks up at a staircase leading to an open door. The breeze she’s noticed is coming from up there. “- And then up onto the roof.”

“That’s what we were thinking.” Carroll pauses. Clears his throat. “Any idea what it is?”

Susan shakes her head. Crouches down. A trail of black dust lines the floor and when she touches it it has the same rough, grainy texture she’s noticed at both the other crime scenes. It’s a sign that this is definitely one of her cases. “We need to analyse this,” she says.

“Already happening. But the other scenes – they didn’t show anything?”

“No, sir.” She pauses again. Carroll hasn’t been working on the case. She’s been in charge. But today he came all the way here before her. “How many dead?”

“Thirty-two.”

Carroll’s tone is hollow. Susan straightens up. Shakes her head. “The roof?”

“Seventeen bodies down here. Fifteen up on top.”

“Can I take a look?”

“Why do you think I called you out here?” Carroll smiles weakly. “Apparently you’re the expert on this.”

“I’m having to learn quickly, sir.”

An officer ties a smog mask over Susan’s mouth. She doesn’t move. Stays so still she hardly breaths. But she hates these things. The air tastes disinfected through them and they itch. Necessary, though, if you’re anywhere below the Second City and you’re going outside.

They climb the stairs together, her and Carroll, and like a gentleman he holds the door open for her at the top.

Susan wishes he hadn’t. She wishes he’d let it slam on her, let it push her back down the stairs.

She freezes in the threshold, looking out over the rooftop. The smog swirls. Shifts, like a living entity. It catches the lights from the cities above and reflects it back to them twisted, distorted. And the empty eyes stare back at her out it.

The bodies rise out of the smog like graves. Heads twisted. Eyes unfocused. Some are pierced through the skull. Some have broken necks. All dead. Gone.

Something scrapes across the rooftop, the only sound in a silent night, and Susan steps backwards into the building.

“Detective? Is it like the others?”

Susan nods. Carroll shuts the door gently, looks down at her with concern. She clears her throat. “Yes, sir.” Her voice is hoarse. She doesn’t like it. She tries clearing her throat again, but it doesn’t seem to want to work. “But  well – bigger, sir.”

“Bigger?”

“More damage. More deaths.”

“So whatever this is – you think it’s getting worse?”

Susan glances at the closed door and tries not to consider what’s on the other side. “Yes, sir. I think so.”