"Eins, zwei, Polizei,

Drei, vier, Offizier,

Funf, sechs, alte Hex..." - a common German nursery-rhyme.

Footfalls and heavy breathing echoed across the tunnels. The fixed lights streaked and bounced as Matt ran through the darkness. The centre of his vision was clear but the streaks were lazy, slow. Run faster. Stay in the centre of the tunnel and there'll be no bricks, no steel to trip you up. The route was wide, with only shadows and ceramic tiles in sight and the torchlight flickered erratically behind him and illuminated unknown shapes. Did Raynes put the home key in the door behind us? Will that slow them down? They'd heard the distant voices get furious, barking orders through Lana's radio as Matt had followed Lana and Raynes weaving their way through the facility linoleum.

"Hale, drop the high-vis! Get it off!" shouted Raynes from behind. He half-turned to see the others gaining on him of the corner of his eye, their long shadows projected and bent on the walls. Matt shook and struggled to take the jacket off. He threw it somewhere to the side to be lost in the darkness. Not far now, he could see the door to the pedestrianized public section of the subterranean walkway illuminated. I don't have to get that far. We turn off before that-. He flinched. The air above him went rigid and exploded into light. The sound echoed and blasted its way through the underground again as Raynes fired at something behind them in the blackness. Matt tried to pretend he'd misheard someone scream over the ringing in his ears. Don't look back. Whatever you do don't look back to see. The way before us is clear.

"Hit the floor!" It was almost a whisper, muted and underwater through cotton wool and ringing from the gunshots. Matt jumped for it to the side, just covered his ears and fell flat. The air above him cracked with firecrackers and deep set pressure-blasts. He scrambled back and to one side, shoving aside bricks and trash. There was a smack next to him where Amy had laid down heavily in the darkness. He felt a moment of terror and his eyes jolted across her to try and see. No, she wasn't hit. From the far end there was the crouched outline of men with star-flashes of gunfire lighting up the tiles of the tunnel, and closer somewhere the quieter high-pitched precision of Raynes firing from a barricaded side-passage. The crouched figure of Lana just hid in the alcove with him. Amy was mouthing something at him. Screaming too, as loud as Raynes.

"The report, Matt. Do it! It's almost time."

"Which one?"

"April's. Forget the keys."

He'd trusted her this far, and the keyboard was still there in her backpack. That's what they'd agreed to do back at Lana's office, to follow the plan and try again. But then again he had a debt to pay – a debt for infecting April and Amy with this insanity, for forcing them all into something he didn't quite understand. He turned onto his back to tear the folded report out of his jens. The front page was dark and strobed white to burn into his mind when Raynes fired. He caught the first few words written in block-serious capitals. S552 ACCELERATOR 'ATOMIC VICE'. The wording mattered. He started chanting the words in his head and scrambled to try and crawl his way closer to one of the hanging lamps lamp, then froze when his movement yielded a hail of whip-cracks above. Raynes fired again and Matt saw one of the dark figures fall, their star-muzzle flashes ricocheting up into the tiles.

"Stay the fuck down! Don't move!" came Raynes' strained scream before it was drowned out by gunshots.

POWER MAINTENANCE REPORT. He put the two segments together and chanted. What if the phrase was too long? How long was the mystical window for him? Seconds? Less? Was it too weird of a double-meaning? Did it matter if he knew what he wanted the report to become? He closed his eyes to the gunfire and tensed up. He felt for Amy's hand, caught it and chanted his mantra. Focus. For once in your life focus, do this. Get it right. Amy's done so much to help us. She's planned, and pushed, and forced us to work this out. April too. Even Scott's pulled his weight. Now it's your turn. He clenched the report in one hand, Amy's hand in the other on the cool concrete and hoped it would be enough.

There was a moment he thought his senses betrayed him. The report flashed, felt hot as if he'd just picked it still warm from the printer. I've been shot, he thought. But there were no dark patches on the grey report, only dark illegible words. Through till images he saw Raynes step out of cover and walk calmly towards the final figure in the middle-distance, crouch and fire. The main tunnel descended into unsettling ringing. Matt stayed where he was, and realized that Amy's hand was shaking just as badly as his. His head swam when he sat up, and swam again when Raynes helped him to his feet. There was a dead tiredness those sunken eyes that checked him over for ricochets. Matt and Amy went on ahead, shaking and stumbling in a half-jog. Raynes went back for Lana.

"Did you do it?" she asked.

Matt nodded, and stumbled his way to the light. She followed, and reluctantly Raynes dragged on behind, ever-vigilant and wary of the unmoving outlines on the other end of the tunnel. The report's main page was the same as before and Matt opened it. Table of contents. He flipped to the first page, which was an introduction but not one he'd ever seen before. It was an introduction to something else entirely.

'It had been loosely hypothesized for some years, particularly in the 2070s that non-normal particles could exist, though such hypotheses did not initially gain much support (Tetra et al, 2074), (Wilhelm and Kos, 2077)...'

He read the dates. What the fuck. Matt skipped onwards.

'Such non-normal particles do not manifest under normal conditions in our universe even if they bombard it externally, as was shown might be the case by Berg et al, 2136. In fact, it is the fundamental laws of physics which govern our universe that act as a defensive mechanism against attack from these rogue elements. By constraining our universe to fundamental 'laws' in our ten dimensions (three spatial dimensions, one being time and six others) the universe acts as a 'walled garden'. Almost anything that enters our universe but is incompatible with its constraints appears to be deleted, and hence our universe is able to survive the attack from the chaos beyond.'

He finished, read it again. "The first part's a research paper," he said. It was an introduction to power maintenance, an introduction to a report how what was happening to him was maintained despite the universe unravelling and screaming at him to stop, to make everything go back to normal. The dates etched themselves into his mind and seemed to add onto the pile of nausea welling up. "It's talking about how the universe stays stable, from somewhere in the next century."

"So it's like Ichor?" asked Amy.

"Just like Ichor, but two-hundred years, not five-hundred."

"That's a good start."

He flicked through further. The introduction cut off abruptly and the second page was blank. He looked further. Some parts of the text were unchanged, and the report was a patchwork of graphs, nonsense and inserted parts where the altered and unaltered new meaning of 'power maintenance' clashed. Where there would be no double-meanings or where he couldn't imagine what a change would look like he realized that the text didn't change, or the changes to it were limited. Where he could pick out a way that a double meaning could exist, however, it had changed. An introduction to the origin and maintenance of these strange powers was in the text because he could imagine how the double-meaning would work. The research paper was unexpected, but Matt saw that other headings like 'liquid helium adjustments' stayed as they were originally. Apparently liquid helium adjustments just didn't have any relevance in the other context of his ability.

He flicked further and got to a section marked 'maintenance solutions' filled with new graphics, pictures of exotic materials, particle interactions, squiggles and lines and runes that he supposed would tell him how to solve this, bring it all under control. But he couldn't begin to understand what chemistry and exotic solutions he'd need. And near the end was the section that he thought might work, and was what April wanted him to see in bright capital letters.

PREVENTATIVE ACTION POINTS. The report originally included a section on how to limit wear and tear on the accelerator's parts. But here, and now, preventative action points on the powers gained from an S522 accelerator meant something wholly different. He read the first line.

'There are multiple ways of limiting the effects of non-normal interactions from rogue events that successfully breach the defences of our Universe from somewhere beyond. The damaged time-lines they create can be removed if the rogue element is forced into self-destruction. In the textbook case from the alternate world in which powers were maintained through an anomalous interaction from an S522 'Atomic Vice' accelerator the-'

Textbook case? He was a textbook case? Matt closed the report. Did people in the future know about this? How? He frowned. The text said from the alternate world, so was he in some land far, far away from the perspective of whoever wrote this report? He stopped abruptly when a shadow fell opposite him and he saw the exhausted secret agent come into view.

"What is that?" asked Raynes.

"A report on the accelerator," he called back. The agent nodded wearily. He'd been too far away with Lana and Matt hoped the gunshots too strong for him to suspect they'd used their only chance for the next God-knows-how-long on this piece of paper rather than on trying to make the keys.

Matt forced himself to fold the report. Something in those last words ate away at him. The rogue element can be forced to self-destruction? If he was doing this, was he the rogue element responsible for destabilizing the world, for causing this madness?

"Let's get out of here," sniffed Raynes. Lana followed him, eyes darting from one lamp to the next. "Time for a real diversion," he said. He listened one last time through the radio channels, couldn't make out anything above the ringing in his ears. With some grim amusement he realized he couldn't even hear the static and shut it off. "How long do we have until Matt becomes useful, Amy?"

"I don't know," she lied. "Still a while."

Raynes nodded, headed down the side corridor and dropped an empty magazine. "It'll end just like Dubai after all," he added to no-one in particular.

***

Scott stood to one side of the curtains and snuck a look down to street level. The entirety of the street further up by the Huxley Maths building was blocked off from the earlier explosion of keys, cordoned and caked solid with vans and black-clad specialist units.

"Schofield how are you doing?"

"Terrible."

All semblance of organization had gone from the office. Files lay scattered on the floor, the coffee table was bloodied and slowly seeping from Schofield's darkened bandages. The huge man wheezed and took a swig of the white wine from Lana's top shelf. What was taking so long?

"How long has it been?" he asked.

"Twenty minutes? Maybe more." There was a clock above Lana's door but the batteries were dead. Scott looked through the curtains again and out onto the street. "They're piling more police out of vans. What's CTC stand for?" he asked.

Schofield perked up. "What?"

"CTC, what is it?"

"Scott, back away from the window. Did you move the curtains?"

"No."

"Could they've seen you?" Schofield pointed pale at him and struggled with the sofa. He growled and tried to get up, dropped the wine. "Is that what's out there? You're positive."

"They've got riot shields. It's what it says. CTC."

"Get April up. We're going," barked Schofield. "We've got to warn Raynes." He contorted and propped himself up on the sofa to stand. "If CTC are here then we need to get out, as far as possible."

"Why?"

"Because our time's up." Schofield shook April, got barely any response. Maybe Navari will help us. Maybe she'll pull through, he thought. "They'll evacuate everything within a half-mile radius. Tube bombings, buses, terrorist cells, they're the ones who mop it up."

"They're anti-terrorist?"

"Militant counter-terrorist special forces. They have powers to obliterate anything Scott. Anything at all."

"They might not come here."

"Listen to me. It's not something that might happen. It's an inevitability. It was always inevitable, I just hoped we'd have more time until they searched all the buildings. Hand me my gun. For God's sake it's not even loaded." Schofield dragged one of April's arms. She groaned. "Help me here, Rowenstein. Open the door. Are they here?"

Scott ignored his request. "In your condition you can't lift her-"

"Which is why I need you to get her awake. Here, forget the door, I'll check." Schofield dropped a box of ammo onto the table. He limped. "And take that box. Do you know how to open and reload one of those?" He pointed to the bloodied table.

"No, but I'll try."

Schofield hissed in pain and leaned out into the corridor. It was quiet. "Pull the trigger hard enough or cock the hammer back and it'll fire. Put five in there, the sixth in the top barrel empty so you don't accidentally blow your legs off. If five shots doesn't do it, then it's too late with CTC." Schofield closed the door "No one yet", he sighed and picked up the wine. "Did you reload it?"

Scott closed the gun shut. Each bullet was almost as thick as a finger. "Yeah."

"Then pass it over."

"What?"

"Scott I know how to shoot. Just give me the gun back."

He dropped the revolver on the table, pulled April up to a sitting position on the sofa and managed to get her to open her eyes a little. "Scott?"

"April, we're moving. We've got to go."

"No," she groaned, her speech slurred with the effort. "It's so far away. I'm not made for here anymore. I'm made for something else." She slumped down.

"You're going to have to," he replied. He didn't want to slap her awake. But there was another option.

"Gah! No." April leaned forward and blinked. Schofield's bottle of white wine dripped from her hair and down the back of her neck. The borders in May got a bit firmer, touch them and they'd disappear, but she would try to stay in the boundaries, prevent anything from stirring too violently that would wash the milky picture away. She got up with Scott's help. "Where are we going?"

"To meet the others in the tunnels," said Scott. "And hopefully find the purple city Amy went to when we get the keys back." Lana's desktop had lost a keyboard, and gained a copy of a violet screensaver that Amy knew was a safe bet.

"To the tunnels then," she said.

Scott nodded. "It's not far." But with CTC it was.

***

The corridors got narrower as you got to the turbine room and there was the smell that came slowly and began to overpower all else - an acrid stench of gas and rot that permeated down the corridor and seeped through the brickwork and underneath gaps in the door. Raynes was reminded of his high-altitude training lessons that felt like so many years ago now. Oxygen deprivation can kill in seconds. A room of nitrogen or carbon dioxide you might have half a minute, a bit more with training. Natural gas he hoped would give you maybe fractionally more time. It was lighter than air but not much. He remembered where he'd hidden the wrench. It would only be another half-turn, or quarter turn and the trap would be complete.

He stopped before the turbine room door. "When we get in there, head up the ladder. I'll be right behind you." He put a ripped piece of cloth over his face, opened the door to the turbine room and held his breath. The hit of it was eye-watering and he blinked through the pain to stagger his way to the generators and the chain-link fencing that surrounded the humming transformer. All it needed was a spark, just one would be enough. The wrench was where he'd left it, hidden behind one of the casings in the disassembled generator.

It was going to be exactly like Dubai, he thought as he took off the ruined lock and went to the side of the transformer to open the control box. There was a bank of trip-fuses and he went through the row. That one. He had wire, just needed to bind it and force the fuse to stay on no matter what happened. Raynes took a cautious breath through the fabric in his suit and resisted the urge to choke. There was wire somewhere in the toolbox by his feet and he scrabbled to find it but couldn't. At the ladder Lana had started the climb up. He tried to think, to come up with any solution fast. Time is of the essence now more than ever. There'd been worse times, he told himself, but he couldn't think of many. His head swam as he looked through the toolbox and found a good enough alternative. Nails. He took a hammer and nailed the trip-fuse through. It would never trip again. The hammer was dropped onto the floor and Raynes slid underneath the broad fins of the behemoth to fix the wrench to its underside.

The whole thing was a huge silver animal of a transformer, finned with barbs like a gigantic death cap mushroom that whirred and hummed hot to the touch. He forced the wrench over a bolt slick with oil and grime. Shallow breaths. Raynes heaved and struggled with the bolt on the underside of the transformer caked shut and blackened with honey-thick grime. It gave way with a rain of rust and he unwound the last half-turn as fast as he dared. Towards the end he stood up out from beneath it and of the danger zone then tapped the bolt free.

Transformers need to dissipate heat somewhere. They're efficient but, with gigantic coils thrusting power to an entire department, some of the power is inevitably lost and warms the machine to scalding temperatures. Most transformers dissipate heat in oil and sit there slowly cooking themselves as they convert their power. Raynes let the oil gush and was thankful for the Doc Martens for some protection. It would overheat slowly, working away until it tripped the low-oil circuits to shut it off. But the circuits wouldn't trip. Job two done. Old echoes of powerpoint trainings long past in an unassuming lecture theatre came back to him. Unassuming faces using laser-pointers on diagrams that showed substations and transformers. You. Third row. Yes you. What then? After you've sabotaged a transformer, what next? "Then we get out of there." Damn right. He threw the wrench to the floor, and backed away, knees scalding from drops where the oil had splashed and which now puddled ever-darker and thicker beneath the finned machine.

He gagged and jumped to the ladder, felt his arms so distant, sluggish, and as he climbed it got harder. Just keep going. There can't be many more rungs. He pulled himself free at the top and staggered a few steps. Just a few more steps further, he thought. The gas is going to get easier once you get through the far door. He saw the arrows he'd marked on the walls, gasped and spat. It was just like Dubai. He followed the arrows, ducked under the hot water conduits and ripped open the door. He rounded the corner to come face to face with Lana.

"I let the kids go ahead. It's this way. You didn't pass out?"

Raynes shook his head wearily. "Almost."

"Did you do it?"

"It's set. It could be five minutes, or less."

Lana checked her watch. It turned out to be less.

***

The other two who'd left Lana behind traced the arrows backwards and walked as fast as they could. Left here. Not far now.

"What did it say?" asked Amy. "Did you get anywhere?" Please let it be easy. I want this to end. She felt like she couldn't breathe, and try as she might her whole body felt colder than usual. The hot and cold still fought, but there was a third feeling too. It wasn't Matt-made, it was just pure terror. And then added on top of it was the light-headedness. It's just the gas. I'll feel better when I get above ground.

"Here," he replied. "Page 45." She took the safety report, and flicked it open. PREVENTATIVE ACTION POINTS. She was dimly aware of Matt leading her through the tunnel maze. She read it once, got lost. From the top.

Calm, Amy. Stay calm.

'In this case powers were maintained through anomalous interactions with particles that were able to manifest spontaneously in an S522 'Atomic Vice' accelerator. The destructive effects manifested as a class IV-level event. The user – identified in this case study as MATTHEW HALE we know was left with the ability to alter both physical objects and non-physical concepts with an alternate version of a Kevanis-field physical law centred around a homonym. The extent of control varied-'

"Matt." She stopped. The feeling of breathlessness had coalesced into a pit now. It stayed there waiting to rupture and overwhelm her. After all we've been through I can't panic now. "This mentions you by name."

"What?" he turned.

"Here." Amy showed him.

Matt read it, his own name capitalized like a specimen. He didn't feel much in the moment - not surprise, or anything else at the news. Some part of him was worried that all he felt was mild interest and weirdly, hopeful. If there was a case study then there had to have been data, and that meant that somewhere, in some universe far away where the person who'd written this article they'd figured out what this anomaly was, had studied it.

He read the rest aloud, hoarse, dry, and barely audible "-the extent of control varied. Ultimately the use of homonyms could theoretically be effective at mitigating and even destroying the anomaly. Here, I outline a theoretical mechanism for reverting an infected world, based on combining a number of extraordinary artefacts which we know each existed in at least one timeline of the AV event. Had these elements been added together we report here that they might've been able to revert the damage and-"

"Revert it?" Amy tore at the page to read further. "What does it mean by combining artefacts?"

"It means that there are different ways this could've played out. Amy, you came from a place that had its own version of me, right? It's possible that version of me made different decisions and chanted different words."

They stopped. She leaned against a wall. "And 'AV' stands for Atomic Vice? This is just one case of many?"

"Maybe. You say you went to a different world. It's possible there are lots of places like that. The people from that article just knew how to research it."

And Amy read onwards and found out how they could defeat the Atomic Vice and its anomaly. And she only stopped reading once they heard the sound 'halt' and the stooping figure of Schofield supporting himself on the pipes, pistol in hand. There wasn't much time left. The CTC had begun their evacuation across campus. And when Raynes and Lana arrived she showed them to an exit through the tunnels that would go to the back end of the Physics building.