I was pretty confused when I saw Connor stop next to me, out the corner of my eye, as I stared through the window into the lab.

'What you still doing here?' I asked, before he got a chance to start a conversation and steer it in a direction I didn't want to go.

Connor sighed. 'Lester sent Danny instead. Told me to stay here.' And his obvious disappointment bleed right through his tone.

'Danny?' I repeated questioningly, 'Danny doesn't even work here.'

'Believe me, Miss Havisham,' Lester interjected as he overheard us on his way back into the hub, 'I am very aware of that fact. I didn't have much choice in the matter considering my only other option was comic book guy.' He continued to walk straight past us.

At the mention of him, I turned my head to Connor. As soon as he met my eye, he sighed. 'So, you're hearing voices?' he asked.

'No,' I replied. Because I didn't want to lie to him but strictly speaking that was the truth; It was just the one voice.

Undeterred, Connor continued, 'is it him?'

'...What if he's here?' I replied sorrowfully, 'I mean, he died here, is it so difficult to believe that he might be trapped?'

With the realisation Connor exhaled, 'that's why you've been… with the mirrors.'

I didn't want him to get stuck here in this plain of existence.

In reality, I didn't know what I believed about souls and death. Sometimes it was easier to believe there was an afterlife, sometimes it was easier to believe there was nothing. That you just rot. Because existence seemed so fleeting in the moment anyway that I doubted I would even remember having lived at all once I was dead.

Nick was in my head. I knew that.

And I knew it wasn't helping.

'Sid?' Connor's voice didn't help my confusion.

I looked suddenly back to the window. I could just about make out the shape of our pet Diictodon in the vent through a gap in the clumps of fungi ash on the glass.

'That's where you are!' Connor continued.

I could feel my forehead condensing to a frown. 'Connor,' I said, 'what the hell is he doing here?' I gave Connor time to answer, but his mouth just opened and closed awkwardly. 'Why isn't he at yours?'

Instead of trying to answer me Connor turned on his heel, making his way back towards the doors of the lab to retrieve our pet from the vents.

And it was a good job the fungi were dead because the idea of Sid breathing it in from the air, and getting an infection in his lungs was–

'It shouldn't have exploded.' I gasped at my own sudden realisation and cried out, making Connor jump and whip around, one hand on the door handle just as he was about to push the lab door open. 'No! Connor don't!'

He came back towards me. 'What?'

'It shouldn't have exploded,' I said again. 'It should have shrivelled.' As his eyes narrowed questioningly, I glanced back to Lester across the hub just to check he was paying attention too before I continued. 'What happens when you put salt on a slug?'

Both Lester and Sarah turned to look at me.

'It dries out,' Connor answered.

I nodded. 'The salt absorbs all the moisture and it dehydrates. What happens if you try to fire a pot before it's completely dried out?'

A shadow of confusion passed over his face. Connor didn't know about pottery. He didn't know anything about kilns or carbon trapping or moisture in unfired clay.

'It explodes,' Sarah answered. I looked to her and nodded.

'Because moisture expands. We see it in the weather... in high humidity the more water that evaporates in a given area, the more water vapours rise into the air and all we get is a thunderstorm. Meaning we didn't kill that thing at all. And, fungus reproduces by spreading microscopic micro–organisms in either soil… or air. That's not ash, it's spores. If Danny tries to grill it, it'll spread through half of London.'

Immediately Sarah pulled out her phone. I watched her dial furiously before she lifted the phone to her ear. 'Jensen?' The other end must have connected. 'Don't use the flame throwers. Don't do it–' Sarah pulled the phone away from her ear. 'They must be underground. The signal isn't going through. Jensen? Jens– No! No, listen–' She groaned and lowered the device. 'Cut off.'

'Try again.'

She nodded as she redialled the number, put the phone to her ear and waited. She shook her head. 'It's not working.'

'How quickly can you get down there?' Lester asked.

'No, there's no way we'd get there in time, it's miles away and–'

'Jensen!' Sarah must have got through to him again somehow. 'Do not use the flamethrowers!'

'So, if we can't burn it, how do we get rid of it?' Lester continued.

Sarah's message must have made it to Jensen, because I saw her exhale with a huge sense of relief and push her hair back from her face.

'Air has properties,' I replied, 'it takes up space…'

'…'

I took a breath, ready to continue before I realised there had been no one to carry on while I had to pause to inhale.

He wasn't here. I'd have to do it myself. My open mouth quivered, just for a moment, as my brain had to moved back to the word I had internally skipped before to allow him to say it for me.

The silence was telling.

I had to swallow the lump in my throat.

'Mass,' I continued. 'It's affected by heat and it exerts pressure– it has a weight– and it can expand. We have to do the opposite. We have to thin it out.'

'You mean shrink it,' Connor agreed.

'Like at altitude,' I stated. 'Drop the temperature. Low as it'll go.'

Connor threw himself back against the thermostat and didn't stop pushing the button until the machine maxed out.

And we waited, pressed up to the glass, watching for any sort of change in the formation of the spores, both on the glass and covering the walls and floor.

I held my breath, not daring to consider what would happen now if I was wrong. 'Don't worry, sweetheart. When have you ever been wrong before? Except about men, in general.'

'I don't do being wrong,' I hissed at him in response.

He cracked a smile. 'Atta girl. I know I didn't always believe in Connor, but never… not even once did I doubt you.'

'Maybe you should have…'

But my words were drowned out by Connor's shout of excitement as a clump of growing fungi suddenly started to shrink away. 'Yes! Yes! Look, brilliant.'

I wiped a hand across my cheek to catch the tear before anyone saw it. 'Good, good,' I mumbled, more to myself than anyone else, and suddenly started to wonder if that meant I could go back to my office now.

'Let's get a refrigerated truck out there,' Lester noted from behind me.

Connor's hand dropped down onto my shoulder. 'Well done!' he said.

I could barely manage a weak smile in response. And when I looked up, I couldn't meet his eye; Nick had so much faith in me it had blinded him. And I was not infallible. The longer I went without making a mistake lured people into a false sense of security and sooner or later it would let them down, just like it had with him.

'…just keep it busy until the freezer truck arrives– I don't believe it.'

'What?' Connor's voice brought me back into the room again, and I looked around to Connor and Lester.

'Danny just hung up on me.'

'Oh?'

'And he said he was bringing the other creature back here.'

I frowned. Oh great. So much for getting back to my office.

'What the hell are we supposed to do with it?' Connor groaned.

I looked away from Connor, found him in the centre of the room, arms out and gesturing to the huge empty space of the hub. Okay. That could work. I nodded at him, and catching a glimpse of the action, Connor started to frown at me.

'A?' he questioned. 'What?'

'We're gonna turn this whole place into one big freezer.'

We rerouted the airflow from all the air–conditioning units from the nearby labs through vents in the wall into the hub.

It didn't take long; we were able to source a load of spare aluminium air tubes from a supply cupboard.

Connor adjusted the thermostat again, and from a makeshift system rigged up to Connor's laptop inside my lab Sarah switched on the air–conditioning.

'It's working. In a few minutes time this place is gonna be colder than the north pole.'

'We need 5 more minutes,' I replied, glancing up at Connor just for a second as I continued tightening the nut around the air pressure cap with a spanner, 'find out where Danny is, we need to be ready as soon as he gets here.' As Connor nodded, and reached for his phone, I cleared my throat again. 'Right everyone, get out!' I called, to instruct the rest of the faculty to get to safety. Following my call, people started moving quickly to the exit. I looked up, caught Lester's eye as he lingered in the doorway. 'Go on,' I repeated, 'we're almost done.'

Lester gave me a firm nod and turned on his heel to follow the others down the corridor.

'You do intend on leaving at some point, don't you, sweetheart?'

I tried not to look up at him, let him distract me, as he stepped into my peripherals and crouched down beside me. I didn't respond to him.

'Anna come on, don't be stupid.'

'So now I'm stupid?' I returned, then, with the sudden realisation I'd said that to him sometime before I dropped the spanner and lifted a hand to my face to press firmly against my forehead like I was trying to push that memory away. 'Oh god, fuck, fuck!'

'Calm down.'

'Don't tell me to calm down, you're dead.' My hand slipped down to cover my eyes, and just to make sure I still didn't catch even a fleeting glimpse of that echo I shut them too. 'You're gone. And… I don't know how to do this anymore.'

'Sweetheart, hey, come on.' It took me a second to steady my breathing. I didn't want to start crying again. I pulled my hand down my face. 'So you lost me… don't lose yourself. You belong here.'

The hub doors flew open, and my gaze snapped up to Connor. 'Anna,' he said, panting, 'we've got to go, now!'

'I'm not done.'

'Anna, the creature's broken out of the van. We could have 30 seconds before it gets here.'

'Connor,' I returned, 'that won't matter if I can't get this regulator on; as soon as it reaches the minimum temperature it'll start to climb back up. The system isn't designed to keep that much of a building that cold for that long.'

He nodded quickly and took a couple of steps towards me. 'I'll help.'

'No,' I said. 'You need to find the creature. It'll be hiding somewhere dark. You need to flush it down that corridor and through those doors.'

I reached down to picked up the spanner from where I had dropped it and grabbed the regulator to fit into the junction box.

'How am I gonna do that?'

'Frozen carbon–dioxide.'

'…fire extinguishers…' he said, in realisation. 'That's good. That's really good. What about you?'

'I'll be out of here by then,' I answered. 'Find the others.'

He nodded as he turned, running back towards the hub doors, I took a deep breath. Then, just before he reached them he slowed and came to a stop. He turned back around. 'Tell me you can make it,' he said suddenly, and with a firmness to his tone that I hadn't expected.

'What?'

'Tell me you know you're gonna make it out of here, in time,' he continued.

'Connor,' I returned, 'I know I'm depressed but I'm not gonna off myself, alright.' Not like this.

'Okay,' he replied, 'sorry.'

'It's okay. Go.' He nodded, retreated back to the door and grabbed the handle. 'Connor!' I then called after him. He paused again and glanced back to me. I exhaled a long breath. A lot of things crossed my mind but not having the time to say any of them, I settled with a final nod. 'Try not to let it touch you.'

'I wasn't gonna shake hands with it!' he complained, before he pushed the doors open, and disappeared.