Hell is a feat of engineering.

The Irrigator is massive. The drill is on the scale of something alien, its circumference being the equal of two City blocks. The layer of condensation coating the outside of the drill reflects the flickering lanterns dotting the walls and casts an ominous orange light over the cavernous space.

We step out onto the platform wrapping around the Irrigator's girth. My ears ring with the deafening roar of the drill's innerworkings and I strain through the eerie halo of water droplets to see the very top and very bottom of the gargantuan machine.

The top of the Irrigator continues on high over our heads, disappearing into the roof of the underground chamber. I crane my neck and peer upwards through the mist. If I concentrate I can make out a network of smaller water pipes stretched across the roof and connecting around the width of the Irrigator. Dozens of tubes, each with its own specific destination, running from the Irrigator to each of Babel's various aboveground water outlets.

I rake my eyes down the length of the drill, noting the way its smooth metal exterior is pocked by patches of steel sheets and screws. The mechanical beast shudders and whirs violently, casting droplets of water over the ledge of the platform we are standing on. The floor prevents me from seeing anything below our feet and the various patrolling Enforcers block me from moving closer to the ledge.

A sense of dread sits heavy on my chest. I have a feeling that I am just seeing the tip of the iceberg. One thing's for certain; I need to get closer.

"Keep moving." Lara nudges me with her bony elbow and I start, tearing my eyes away from the Irrigator and falling into step behind her. The circular platform below our feet is carved from the stone walls and wraps around the entirety of the Irrigator. Enforcers, clad in their trademark dark, layered garb stand at various states of attention around the perimeter of the chamber. The display reminds me of something I've seen before, deep in the Palace gaol.

The difference being that this time I am unarmed and a good deal further from escape. My disguise isn't a sword and a gender; it's a trayful of food and a scantily-clad traitor with comely hips.

At this moment Lara is swaying said hips as she strides towards the first Enforcer reclined against the wall.

"Hey, Lara. I was hoping you'd be coming by today." The man, little more than a boy, straightens at our approach and flashes Lara a dimpled grin. "How have you been?"

"Hello, Gus." She smiles back, but it isn't the false, sickly-sweet version she reserves for her paying customers. It seems genuine. "I've been well, thank you."

"Glad to hear it." He nods to me, extending a hand. "Pleased to meet you. I'm Gus."

"Abby." We shake.

"Abby is new to Babel. I'm showing her the ropes." Lara brings her tray down, expertly plating an assortment of food and handing the assembled bowl to Gus. "She's never seen the Irrigator before."

"No kidding? It's really something. Do you want to take a closer look?"

"I'd love to." I say, with what I hope is the appropriate amount of eagerness.

"No problem. One word of caution: there's no barrier and the damp stone can get pretty treacherous at this height." Gus places his bowlful of food on the ground. "So I'm afraid I can't bring you right up to the ledge."

My heart sinks slightly but I press on. "That's fine, I'd be interested in getting as close as you deem safe." I throw in a shy smile for good measure.

"In that case, follow me." He extends an arm to Lara and she loops her hand through the crook of his elbow. I hang back, letting them walk ahead as Gus leads us towards the drill. I take the opportunity to look back up to the ceiling, considering the network of water pipes overhead as I trace their paths from the various tunnels branching off the main chamber. I turn the possibilities over in my mind, biting down hard on my lip as I think.

"I'd say this is far enough." Gus instinctively catches Lara when she stumbles on the slick ground. "There she is. What do you think?"

I lean out past him, vying to peer down into the hole. We are still a good ten feet back, too far to see much of anything. There is a heavy mist obscuring most of what lies beyond the drill, but if I concentrate I can make out the occasional flash of movement from the lower levels.

I unfocus my eyes, blinking and looking back towards the Irrigator. "It's unlike anything I've ever seen. How deep belowground does it run?"

"Let's see. Right now we are at about fifty feet, and I believe at last count the Irrigator was pushing another hundred and fifty below us." Gus scratches his head, jostling his scarf. "We move a little bit lower every day, always chasing that water."

"Right." I breathe, stretching my eyes wide so as to appear full of wonder. Internally I am screaming a litany of curses out of frustration. I am close, but I still need to get closer.

"If you're satisfied, I think we should move away now." Gus releases a nervous laugh. "I'd be given a remedy for certain if I lost you over the edge."

I step back, pasting a smile on my face. "Thank you, Gus."

"Anytime." He may be speaking to me but his eyes are trained on Lara.

"Well then, should we continue on?" I shoot Lara a look, eager to complete this chore so that I can find a way to overlook the Irrigator.

"Yes, I suppose we should." Lara sounds somewhat reluctant but follows me back to where we left our trays, shouldering the weight with a professional grace. "I'll be seeing you around, Gus."

"Stop by again soon." Gus gives her a boyish grin. "I'll be here."

Lara's movements are noticeably lighter as we continue our deliveries. For my part, I study the Enforcers, watching their movements and following their eyelines. The majority of the men appear bored, leaning back against the walls or strolling aimlessly around the curved platform. As has always been my experience, no one seems to have any concern for what is below their feet or what may be going on over their heads.

At once I make up my mind. I urge Lara along and together we manage to efficiently deposit a bowl of food into each Enforcer's hands before making our way back to the entrance of the tunnel we arrived from.

"What's your plan?" She demands wearily, allowing me to pull her into the shadows against the wall. "We don't have much time left."

"I'll be quick." I hand her my empty tray and step out into the passage, checking back towards the main chamber to make sure no one is watching before looking up. The water pipes run very near the carved-out ceiling, leaving only a small gap for me to squeeze into. This is going to be interesting.

"Gus is the only one who might be close enough to see me. I need you to keep him looking elsewhere." I explain, turning in place as I study the pipes.

Lara's silence tells me that she is working out my intentions. "I don't think this is a good idea."

"Not to worry, I don't need you to think." I run my hand over the stone next to me, committing its slick texture to memory.

"Fine, then, have it your way." She stands back, hugging the trays to her chest as I make a run at the wall, kicking off the side of it and propelling myself up towards the pipes, grabbing hold with outstretched hands.

The pipes are damp, clammy and much, much colder than I anticipated. I grunt, my fingers slipping repeatedly as I grapple for purchase. With one mighty heave I manage to pull myself bodily up, bumping my head on the stone ceiling as I flop inelegantly down onto my stomach.

"Graceful." If Lara's tone were any dryer, it would be dust. "You always had more guts than brains."

"Just go distract the guard." I hiss. I watch her make her way back to the tunnel exit, waiting a moment for the murmur of voices to drift back to me before easing my way along the cold pipes.

My lightweight clothing does me no favours, soaking through almost instantly and giving my knees next to no traction. After some experimentation I adopt an awkward belly crawl, reaching forward to grab a length of metal ahead and pulling myself forward, using my impractical clothing to slide along the top of the pipes. It isn't the most silent method of travel, but the sound of running water below me does a good job of muffling my movements.

When I reach the end of the tunnel I pause to make sure that Gus' back is turned. I can see Lara over his shoulder, laughing at something he is saying as she slaps him playfully on the shoulder. From the way he was gazing at her earlier, I know I can trust in his attention being diverted for as long as I require.

I look up towards the shaft of the solid steel Irrigator standing up ahead of me, mentally cataloguing the distance and estimating how long I will be exposed for. The most dangerous part of this plan will be the time I spend clearing the distance between the mouth of the tunnel and the ledge of the surrounding platform. After that, the spray of watery vapour should shield me from any prying eyes down below. I inhale a deep lungful of the damp air, sighting my target and willing my movements to be as smooth and still as possible, the way Luca taught me. In the next breath I pull myself forward, exiting the tunnel and making my way out over the open space.

The pace I set is both endless and maddening. I keep my gaze trained on my goal ahead, counting off the distance as I close in on the ledge. The cold pipes below me shudder with increasing intensity, coming alive with the rush of water as I crawl closer and closer to its source.

It seems an eternity has passed by the time I clear the gap and can finally see straight down into the chasm dug by the drill. I unfocus my eyes to keep myself from seeing too much too soon, choosing to use my reserves of concentration towards successfully completing the treacherous journey to the Irrigator. I shut my ears to the influx of sound and imagine the slick, smooth surface below below me as the rocky facade of a stone building, not allowing myself to see anything past the next handhold.

Of course, stone buildings generally don't shake like this.

I push myself through the wall of mist, blinking droplets of water and damp hair out of my eyes. A particularly aggressive shudder passes through the pipe below me and I slip, careening over the edge.

Instinctively I tighten my grip as I fall, desperately curling my fingers into the shallow gap between the pipes. I bite down a scream as I catch my full weight, kicking my legs from where they dangle a hundred and fifty feet above the ground.

I am thrown back and forth, bucking under the force of the trembling pipes as I fight for purchase on their damp surface. Mist sprays at me from all sides, obscuring my vision and loosening my grip.

Gritting my teeth I look up, catching sight of the platform of pipes through the unforgiving rain. With one mighty heave I swing my legs forward, wrapping my legs around the pipes and crossing my ankles. The force of the manoeuvre causes my hands to lose grip and I end up dangling upside down, face-to-face with the Irrigator.

The implausible machine mocks me, drilling away merrily, boring the Earth with violent force as I shake in place, thrown about helplessly by the rush of water.

My legs and abdomen burn with the effort of lifting myself up. It takes a couple tries but eventually I manage to gain a grip and swing myself over the side of the pipes. Once again I assume the belly crawl, my hands now clutching the sides of the makeshift bridge with a renewed force.

Finally, I am within touching distance of the colossal drill. The sound of rushing water is deafening. Pipes surround me on all sides, branching in from the various tunnels and convalescing around the width of the Irrigator, connecting together with a thick, reinforced seal. I ease myself as close to the drill as possible and drop down onto the narrow bridge of scaffolding that runs around the exterior. With clammy hands I grip the handrail and peer tentatively over the edge.

Now I understand why Lara described this place as hell.

There are people down there, countless numbers of them. Dirty, thin, unkempt people milling about in the tunnels surrounding the Irrigator. Hundreds more are scattered upon the ground, the sounds of their shovels and pickaxes echoing off the sides of the immense drill and reverberating through the cavernous space. My ears fill with a cacophony of shrieks and groans. The incomprehensible amount of pain and suffering suddenly overwhelms me, threatening to spill me from my perch.

I choke on a gasp, clutching at the pain in my chest as I swivel my head back and forth, looking around hopelessly for a familiar face. The sheer amount of humanity overloads what little focus I have managed to hold onto and I feel myself quivering from a combination of pure rage and horror.

It's too much.

My left hand slips suddenly on the slick handrail and I stumble, jerking myself back into the present. I step back, pressing my shoulders against the impervious wall of the Irrigator as I fight to bring my heartrate back under control.

The level of suffering, the amount of pain and anguish is physically, emotionally and mentally overwhelming. All those people; Noah, Marc, Will and countless others, trapped in this hellish nightmare of a prison, forced to dig and maintain the Madam's unholy testament to the gods.

The degree of cold-blooded brutality a person must possess in order to enforce this servitude is staggering. This is not humanity, this is heartlessness. This is savagery.

This is hell.

The shuddering in my chest quakes as violently as the pipes overhead as I pull myself back up. With great difficulty I begin to clumsily pick my way back along the length of the tubes, the pounding of my heart pulsing through my head and blocking out the auditory onslaught of the horror occurring below me.

I am searching for my next tentative handhold when an all-too familiar sound cuts through the rushing in my ears. There is the sudden whistle of leather slicing through air and into flesh, followed by a sharp howl of pain.

My shoulders bunch up instinctively, the scars on my back burning as if fresh. The lash falls again and again, it's recipient's moans weakening with each subsequent hit. Blood fills my mouth as I bite down hard on my tongue, forcing my mind back onto the task at hand and propelling myself recklessly above the chasm and towards the corridor, my now-practiced grip remaining sure and steady.

Finally, I clear the veil of mist and close in on the platform above the patrolling Enforcers. I can see Lara is still engaging Gus in conversation, her eyes wide and bright in the light of the flickering lanterns. If she notices my presence she gives no indication, instead grabbing Gus by the arm and pulling him so that his back is turned. I bring my focus back to the length of pipe in front of me, furrowing my brow when I catch sight something strange caught in between the tubes up ahead.

I scoot closer, reaching out a hand to grasp the piece of material fluttering in the draft. With some effort I manage to pull it loose, tucking it into my palm before moving into the tunnel and swinging back down to the ground.

My legs are shaky when I land and I crash inelegantly against the side of the stone wall, sliding down it and folding myself over my knees. I draw great, shuddering breaths as I fight to process what I have just witnessed.

There is so much more than I anticipated. So many people, so much pain and suffering so far below the earth. The scope and scale of what is happening in Babel is positively devastating. The old hurts scarring my back and heart hum with the truth of everything. The situation is far, far worse than anything I previously considered.

At this moment, alone and sopping wet in an abandoned tunnel fifty feet below the surface of an enclosed enemy camp, I have never felt so helpless. Who was I kidding, thinking I could drop in here and pull Will out, easy as you please? Even with our newfound alliance, freeing the Wasters and Miners is going to take a force the likes of which I can't even begin to comprehend.

I cannot see through the haze. A single tear rolls down my face and I swipe at it angrily, the ache I feel at missing Will increasing tenfold. His calm, ready presence is the rock I need to hold on to. If he were here, he would know precisely what to do.

But Will isn't here. He is buried somewhere in the endless pit below.

"I understand, now." I whisper to myself, squeezing my eyes shut tight in an effort to keep the rest of the tears at bay. This pain, this incredible, aching pit of emptiness I feel at knowing where he is but being powerless to help him; this is what he was talking about. This agony is what I caused within him. It is a wonder he held on for as long as he did.

When Lara appears I don't even bother to look up. She slides down so that she is sitting next to me, her arm a hairs-breadth away from mine but not touching.

"I'm so sorry, Kay." Her voice is low and holds a slight tremble.

"How can they think this is right?" I am too tired to feel angry with her, looking up as though she might have an answer.

She shakes her head, shrugging helplessly. "It's what they're accustomed to. Think about it; none but the Enforcers ever see first-hand what is really happening. The rest of Babel's citizens choose to shut their mind to the truth and carry on enjoying their endless supplies of water."

"It's sick. It's madness." I look back down at my clenched fists, registering a distinct tremor. "These are humans, and they're suffering."

"I know." Her shoulders slump as she leans her head back against the wall. "It sort of makes what we endured as Commoners seem like a bit of a cakewalk, doesn't it?"

"I don't know what to do." I hear myself say, dully.

She doesn't reply immediately. The distant hum of the Irrigator drowns out the Enforcer's shouts and the labourer's groans, fading the chaos into a steady background noise. For a moment, the solitude of the tunnels allows us to hear the gentle drip of water against stone.

"You'll figure something out." Lara's calm tone breaks through my thoughts. "If anyone can free us, it's you."

"It's too much, Lara."

"Listen to me. The Madam may have the upperhand but you have something she could never hope to touch." She grabs my hand, her fingers furling around my clenched fist. Lacking the strength to pull away I glance up, arrested suddenly by the determined look etched across her pinched features. "You have heart, Kay. More than I've ever known another person to have."

"What is heart compared to hundreds of feet of solid earth and decades of technological advancement?" I spit.

"Technology fails. Earth crumbles." She squeezes my hand tighter. "You will carry on."

"I can't. I can't help them." My voice breaks and I rub my throbbing forehead with my free hand. "I can't see the way through."

"Look at me."

I drag my eyes reluctantly back up to her.

"I've known you nearly your entire life and in all that time I've never seen you back down from a fight. Defeat isn't part of your makeup." Her dark blue eyes burn steadily into mine. I blink, recognizing the determined look of the girl who vowed to protect me when I showed up on her doorstep five years ago. "You're clever and you're cunning. When you decide that something must be done then the gods themselves cannot stand in your way."

I swallow, unable to find my words. Gently I tug my hand free of her, unfurling my fingers and suddenly remembering the piece of fabric I tore free of the pipes.

"What is that?" She asks, leaning over my shoulder as I study the damp cloth.

My hands begin to tremble. The sand-coloured fabric is rough beneath the pads of my fingers, shocking me with its familiarity. Its edges are frayed, obviously torn hurriedly from the officer's jacket with a heavy hand.

I turn the piece of uniform over in my hands, holding it up to the light and straining to read the message etched out in heavy block lettering.

3 ½ at 12

"What does it mean?" Lara's breath tickles my neck from where she leans in close. I don't respond, my eyes wide as I read the note over and over, finally folding it carefully and tucking it into my bodice. My heart flutters wildly in my chest, filling me with a sudden breathless optimism and spurring me onwards. I scramble to my feet, grabbing Lara by the hand and pulling her bodily back down the tunnel towards the lift.

"What's going on?" She demands, struggling to keep up with my long strides.

"I have to get aboveground." I say, increasing my pace. "Hurry up."

Blessedly, we come across no Enforcers during the long trip back through the damp tunnel. We reach the lift and I jab the brass button repeatedly, jumping from foot to foot impatiently while we wait for the floor to make an appearance.

Our journey up past the layers of dirt and rock seems endless. I take the opportunity to run the words from the note over and over in my mind. 3 ½ at 12. I briefly consider the twelve as meaning midnight rather than noon but dismiss the thought. He would be using military time.

The sudden onslaught of light streaming in through the open walls of the aboveground lift station are a welcome sight. I push the gate aside and race back across the tiled greenspace, in my minds-eye imagining the layout of Babel as I saw it from above, orienting myself relative to the North and South.

"What time is it?" I demand as Lara draws up next to me, her breaths ragged.

"Nearly noon." She pants, sucking in great lungfuls of air. "For gods' sake, what's gotten into you?"

"I have to go." I pick out the Easterly direction before looking back at her. "I'll find you later."

"Be careful." She pulls me into a hug, releasing me immediately when I stiffen in her embrace. A high colour has risen to her cheeks and she looks away, taking a step back.

I run a hand over the back of my neck. "You too." I tell her, nearly meaning it. WIthout another word I turn and sprint away, spurred onwards by the feeling of scratchy fabric tucked against my chest.

3 ½ at 12. The words ingrain themselves in my memory. I imagine the layout of Babel as the face of a giant clock, with the number twelve pointing to the north. Three and a half would be due East, halfway between the centre of the city and the edge of the dome. I glance up as I run, cursing the miniscule opening in the roof, acutely missing the ever-present sight of the sun. I'll just have to pray to my forsaken gods that I'm not too late.

The crowd thins noticeably as I draw closer and closer to the outskirts of the city. People seem to be seeking shelter, clearing the streets in preparation for the scheduled rain. I grit my teeth, pushing myself harder, continually searching through the sparse hordes for a glimpse of a familiar face. My legs burn with the exertion but dutifully continue carrying me onwards. Up ahead I can see a garden and the cluster of low, foliage draped gazebos that I have pegged as being the halfway point between the centre and outskirts of the city.

I slow and stop, resting with my hands on my knees as I draw great, steadying breaths, willing my heartrate back to normal. The gazebos are abandoned; there isn't a soul in sight. I furrow my brow, circling the area and peering around the scattered columns, running my hand through my hair in frustration when I find no one.

Something drops onto my shoulder and I jump, clutching my arm as if burned. I look up, realization slowly dawning. The rain has started.

The grid stretches above me, an endlessly-complicated network of stairs and scaffolding, its dark iron grating appearing in stark contrast to the ground's plush foliage. I briefly consider the lowest handhold and move to the outside of the gazebo, grabbing hold of the white stone exterior.

I pick my way up to the roof, taking a moment to plan my next move before jumping and grabbing the iron ledge of the platform. More beads of water dot my shoulders and dampen my hair but I pay no mind, pulling myself bodily upwards, climbing over the ledge and immediately leaping again, all the while plotting the rest of my route to the top.

The iron is slick with rainfall but my grip is sure, strong, unwavering. The obstacles standing between myself and my next handhold might as well not exist. The frantic hammering in my chest gives me all the motivation I need to keep climbing, time and time again sighting each subsequent anchor an instant before I reach for it.

The ground falls away as I climb ever-higher, wiping a hand impatiently across my eyes and squinting through the mist, straining to see above. The gentle trickle of water turns into fat drops, in the next instant coating everything around me and soaking me through to the bone. I suppress a shiver, biting down hard on my lip as I concentrate and pull myself up onto the final platform.

Straightening, I push the drenched strands of hair from my eyes, turning in place and looking out over the ledge. The heavy rain obscures my view, falling ceaselessly over the iron grid and coating the world below.

I look around wildly, all the while cursing myself for getting my hopes up, for thinking that there was any chance that I would find someone up here. Today I witnessed hell and determined that escape would be next to impossible.

With shaking hands I pull the tattered piece of fabric free of my bodice, studying the smudged letters smeared across its surface. What if I misinterpreted the message? What if this is some elaborate trap? What if the note was never meant for me at all?

I didn't even stop to think before racing out here. Stupid, Kay. I made a sudden decision based on a feeling, immediately tearing recklessly through enemy territory and up through the dome's scaffolding. After everything I've learned, I am still reacting with my heart and not my head.

The iron grating below my feet shudders slightly and I whirl around, my hand flying to my mouth as a figure emerges through the mist.

Rain runs down his face, shining against his stubbled head and beard. He is dressed as an Enforcer, the dark swathes of fabric soaked through and sticking to his chest and shoulders. A white scar cuts across his hairline, accentuating his dark brows and steely grey eyes.

I stay rooted in place, scarcely believing what I am seeing as he takes another step forward. His mouth twitches into that half-grin, droplets of water catching in his familiar dimple.

"You got my note."

I choke, flinging myself forward, closing the short distance between us and letting him catch me against his broad chest. He lifts me and our mouths collide with feverish urgency, my tears mingling with the heavy rainfall as I wrap my arms around him. I can feel his rough hands on my bare skin, pressing us tightly to one another, refusing to let go.

Damn my head. My heart is the one I trust to pull me through.