Tuesday evening was muggy and unpleasant-the promised rains were tantalizingly close, but for now Glasgow sweltered. Sitting alone in his sixth-floor office, staring out of the window at the heat-hazed streets, Will brooded. The rest of the day shift had knocked off hours ago, but here he was, still obsessing about flat 47-122, Sherman House.

He’d checked the scanner logs a dozen times. Gone through the recording with Sergeant Slater. Twice. It was definitely the same place. Kevin McEwen had gone home on Sunday night and blown his wife and children into bite-sized chunks. Drenched the flat in blood.

So how come two days later it looked as if nothing had happened there? Services hadn’t been near the forty-seventh floor of Sherman House for months-he’d checked.

But someone had…

There was a flash of light against the gathering clouds-one of the massive Scrubbers catching a ray of sunshine. Tons of rusting machinery, hanging above the streets and houses, glinting like a big, dirty balloon.

Will closed the blinds.

Director Smith-Hamilton was right: they couldn’t send another team in there. The natives were volatile at the best of times, but three visits in as many days had left them ready to explode. And he really didn’t want to be the one who lit the fuse.

But he wanted to know.

So he went back down to the reconstruction suite and ran the recording again. There had to be something he’d missed.

The first evening is rough: huddling in doorways, doing her best not to be seen. Avoiding the Bean-Heads and the Mincers. Just because they’re little children, it doesn’t make them any less dangerous-all wired and jittering with combat pharmaceuticals. Hunting in packs for fresh meat.

She finds somewhere safe to wait, near the service entrance, behind a pair of industrial wheely bins that smell dark and meaty. The ‘WARNING-BIOHAZARD’ label all scuffed and peeling. For once the bees are quiet, their wings still sticky with Pig-Face and his partner’s blood. Fat and contented. She dozes, trying to ignore her own hunger and thirst…

By the time the bright-yellow council Roadhugger appears the sky has faded from pale blue to dark orange, the city’s sodiums coating everything in sickly light.

The Roadhugger’s warning lights flash as it reverses up to the main entrance, then a man gets out of the cab and goes around to the back. He struggles with the tailgate for a moment then leads his cargo out onto the grubby forecourt and lines them up, ready for work. The previous shift of halfheads wanders out through the hospital doors and the man loads them into the empty bays. Then drives away.

She steps out from behind the bins and joins the line-up. She doesn’t look up at the sign that says ‘GLASGOW ROYAL INFIRMARY’-that would be suspicious. Halfheads don’t take any interest in their surroundings.

She’s slightly dirtier than the others, and her jumpsuit smells, but the bored orderly in green and white doesn’t seem to notice. He just steers them all in through the service doors and starts handing out the night’s tasks.

It’s been six years since she was last here. This was where they cut her face in half, removed her breasts, stitched up her orifices and burned away her brain, but before that she’d been in and out almost every day. That’s how she knows she’ll be safe.

She worked here, hunted here. She knows this building, knows where to get what she needs.

The intravenous nutrients they give to coma patients are almost the same as the ones they use for halfheads. It won’t give her quite as much energy, but she can always take supplements. All she has to do is get to the central store.

When the orderly turns his back she disappears, taking a mop and wheely-bucket with her for camouflage. No one sees halfheads anyway: they’re invisible.

She works her way into the bowels of the building, pushing the bucket ahead of her.

Little has changed down here: the walls are still two-tone institution green; everything still smells of stale sweat, rotting cauliflower, and cheap detergent. There are miles of these little corridors, winding their way through the earth. Laundry, Waste Disposal, Protein Recycling, Incinerators…

Her broken glass memory brings up a face: Gordon Waugh. Long hair, high forehead, piercings. He’d screamed and begged when she’d beaten him, mewled as she’d slid the knife into his belly, popped and crackled when she dumped him in the furnace…

Strange. She can see all that, sharp and clear and perfect, but she can’t even remember her own name.

She stops outside a door marked, ‘AUTOMATED STORE: NO UNAUTHORIZED ACCESS’. The securilock looks new. She reaches out and strokes the buttons lightly with her fingertips, feeling them bump beneath her touch like stiff grey nipples. The display says ‘ENTER PASSCODE’.

Passcode.

She pauses for a moment. Listening.

A pair of thick Fife accents are arguing somewhere off in the subterranean corridors. The air management system rumbles. The plumbing gurgles and clanks. Other than that, she is alone.

Perhaps she should go looking for someone? Someone on their own. ‘Persuade’ them to give her the code. Slice them up nice and thin, peel back their skin like…

She closes her eyes, shudders. The bees are back, loud and insistent. Hungry.

There are drugs in the store that will help control them. Help her think more clearly.

But first she has to get that code.

A sound from down the corridor: the voices from Fife are getting closer. She jerks upright, looking for somewhere to hide. And then remembers what she is: nobody sees half-heads. As the two men turn the corner, all she has to do is pick up her mop and push it back and forth across the floor.

‘No it wasn’t.’

‘Yes it was!’

‘It can’t have been. The peritoneal cavity just isn’t big enough for a whole melon!’

‘It is!’ They walk right past her.

When their singsong voices fade into the distance, she lets the mop fall to the floor and squats down in front of the securilock again.

Frowns at the keypad. Fingers twitching.

She can feel half-remembered shapes-not numbers or letters, but a pattern of motion. A memory written in muscle and bone. Shutting her eyes she places her fingertips against the buttons and lets them find their own way through the combination.

There is a soft ping and she opens her eyes. The display has changed from ‘ENTER PASSCODE’ to ‘CODE ACCEPTED’. They haven’t deleted her old access code. Sloppy.

She steps inside and closes the door behind her.

The room stretches out beneath the building, a vast forest of shelving and racks disappearing into the distance. Automated pickers glide between the aisles, fetching and carrying everything needed to run one of the world’s biggest hospitals. The metal arms load their cargo into the many dumb waiters that pepper the cavernous room, a ballet of steel and medical supplies, played out to the soft click and hum of machinery. It is beautiful.

Human intervention is not required down here: machines stock the shelves from a subterranean shuttle station, machines check the stock levels, and machines carry the supplies up to the wards and the operating theatres and the mortuary and the canteen.

A beautiful mechanical world where she is the only living thing.

It takes almost an hour to find the coma ward nutrient pouches, perched in the far corner, between acres of toilet paper and racks of skinglue. She rips open a box, pulls out one of the flattened jellyfish shapes, and pops the seal, watching as the bag swells with all the things she needs to survive. It will take a minute or two for the mixture to settle and clear and she spends the time digging out an intravenous line to attach to the socket in her arm.