There was concrete to his right, concrete to his left, and when he stood straight, he hit his head on more concrete. Rain led him through the pitch with illogical confidence for someone who was walking blind. He didn't share her confidence. The further they went, the more he resisted, until she gave up and let go of his arm. Sighing, she turned on the light of her palm pod, revealing what he already suspected. They were in the gullet of the stormwater drain, a human-sized warren so small, there was nowhere to go but forward or back, and no room to stand even two people abreast.

Dec immediately broke into a sweat. "Where's Adele?" he said.

"Further down. We're only a few meters from the entrance."

Dec glanced back. He thought they'd been walking for ages, but Rain was right. Behind, the wind made a flute of the tunnel entrance, and he could still smell the distinct clay kiln scent of the dust storm.

"Come on," Rain said. "Just a bit further."

As they walked, Dec saw worrying signs of degradation in the structure of the drain. Cracks in the concrete seeped rust-coloured moisture, and the seams between each barrel sagged. Graffiti tags near the entrance, which still smelled of paint, faded the further they went and were replaced by a rank odour of decay. It seemed whatever had last ventured this far inside, had never come out again.

Probably a rat, he thought to himself.

His suspicion was confirmed when Rain swerved to avoid a small matted, fur ball on the ground, already being consumed by a gathering of more small, matted fur balls. The rats screeched as they passed, their tiny, clawed feet making scattered retreats.

His mother was seated just beyond the dead carcass, with her back against the tunnel wall, breathing slowly through her nose, eyes closed, a peaceful expression on her face. As soon as he saw her, Dec crouched with his back against the concrete. Now that he knew she was safe, there was no need to get any closer and put himself at any more risk of getting sick than he already had.

Rain leaned over Adele and checked her vitals again. Her ministrations were graceful, tender, as one would caress a small child. If Dec didn't know any better, he would've thought she cared for his mother's wellbeing. "Aren't you worried you'll get sick?" he said.

"No," she said.

He waited for an explanation.

None came.

Dec might've been annoyed had he not been estimating how many tonnes of earth and steel were pressing down on them from above or calculating the number of broken bones he'd have if the drain collapsed and they were buried alive. His breathing shallowed and he closed his eyes, trying to quell his rising panic without drawing Rain's attention.

She noticed anyway.

"Water?" Rain said, producing a small bottle from the back of her jeans, where she apparently stored all manner of goods. "Just a sip should do it."

Dec pushed her hand away.

Rain placed the bottle on the ground next to him and sat down. "Sometimes, when I get jhelia-aemosch, I sing."

"Jala-what?" Dec said.

"You know, when you get scared in small places. We say Jhelia-aemosch."

The word was a blur of vowels. Dec didn't try to repeat it.

Rain went on, "In our language, it also means someone who has a fear of intimacy or closeness. People who are afraid to love. The two are seen as one and the same—"

"You get claustrophobia?" he cut in, taken by surprise at the fact.

"Not anymore," she said and began to hum a tune, interspersing it with the vowel-heavy words and inhuman guttural clicking noises like morse code. Dec had never heard anything like it. His mind was repulsed, as it usually was with all things Northern, but at the same time, he didn't want her to stop. He was like a child investigating a squashed bug on the pavement. He couldn't look away.

The song ended with a note, halfway between a hum and a whistle—a sound that had been repeated throughout the song and had been followed by long pauses. He found himself saying, almost in a whisper, "What does it mean?" and was glad for the darkness, which concealed the deep blush that rose in his cheeks at his own curiosity.

Rain turned sharply, as though she'd forgotten he was there and quickly switched back to Southern, which was so plain, it almost seemed monotonal next to what he'd just heard.

"That was an old folk tale," she said, a faraway expression glazing her eyes. "Spoken in a very old form of my people's language. Not many know how to speak it anymore." She paused in thought. "The story goes, there once was a farmer whose only horse ran away. Such bad luck his neighbour said. The farmer said, we'll see. The next day his horse returned, bringing with it three wild horses. The neighbour said, such good luck. The farmer said, we'll see. That day, the farmer's son breaks his leg trying to ride one of the wild horses. The neighbour said, such bad luck. The farmer said we'll see. While the son lay in bed, the country went to war. All the boys from the village were conscripted to fight, except for the farmer's son. Such good luck, the neighbour said. The farmer said, we'll see. All the boys in the village died at war, all except the farmer's son. Such good luck, the neighbour said. The farmer said, we'll see."

Dec was surprised to find the impression of the sounds Rain had made fit the story translation. He could imagine a farm from those sounds, a village, a nosy neighbour. Perhaps the humming noises were the wind rustling through the fields and the braying clicks, the horses. He was struck by a wave of sentimentality as he remembered their farm in Quarry Cove—the straw yellow fields that just kept getting drier every year until the earth was so parched, the crops wouldn't grow and they'd had to sell up and move to the city.

"I didn't know you had farms in the North," he said. When he thought of the North, he imagined big cities, skyscrapers and technology.

Rain said, "We don't. It's a very old song."

After that, they sat in silence for a while, in which Dec allowed himself the guilty pleasure of replaying the song in his head—the braying clicks, the eerie humming. Though he loathed to admit it to himself, he thought the song was the most fascinating thing he'd ever heard.

Rain broke the silence. "Why wouldn't your mother go to the hospital with you?"

Dec glanced at his mum, who was still asleep against the wall of the tunnel. "How would you feel if you just found out you might only have two weeks to live and you had to spend them in a hospital ward, hooked up to machines, like some kind of lab rat."

"Lab-rat?" Rain shook her head. "I don't know this word."

Dec lowered his voice to a whisper, remembering Adele had been able to hear the nurses, even when she'd seemed incapacitated. "A laboratory rat. You know, someone they can cut up and do scientific experiments on."

"Oh." Rain was silent for a moment. "Yes. I know what that is." Her gaze fell on the light of her palm pod, then back on Dec and her words became stilted, as though she'd suddenly lost fluency. "What's wrong with being a lab-rat? How else are the doctors going to improve their medicines?"

Dec stared, aghast. "Is that what all you Northerner's think?" He didn't know why he was even engaging in this conversation. It was pointless arguing ethics with a Northerner.

"Why?" Rain said. "It's for the good of everyone. She should be honoured to be assisting in medicinal advances."

White, hot, rage welled in Dec and he balled his fists. It was all he could do not to lunge at her in anger. "No wonder you're all dead inside."

Instead of pulling out a knife at the insult as he'd expected, Rain merely pursed her lips. "Have you ever needed to go to hospital?" she said.

Dec didn't answer. Of course he had. Everyone had for some reason or another—unless they'd been wrapped in cotton wool.

Rain continued, "Just say you broke your wrist. How do you think the doctors knew how to set your bone?" She didn't wait for an answer. "Because someone did an experiment on someone else, and figured out how to do it. Life is all about experimentation. Our survival relies on 'lab rats' as you call them—"

"Everyone should have a choice about what's done to their bodies," Dec cut in, forgetting his resolve not to engage in this conversation with the Northerner.

Rain cocked her head to the side. "Are all Southerners so selfish?"

"Selfish?" he spat, not bothering to keep his voice down in his anger. "Selfish?! Oh, because you'd know all about selfish. You and your people came here, took over our city and pretended like you owned everything and everyone in it."

"We don't want to be here. We didn't choose to come here."

"Oh, poor you. It must be so hard in your fancy air-conditioned offices, getting to sleep at night and work during the day." He was shaking.

Rain looked away and there was a tightness in her neck that suggested she was holding back as well. "You don't know anything."

"Don't I? Why don't you enlighten me?"

Rain fell silent.

Dec slapped his knee. The sound echoed down the tunnel like a gunshot. "How about you start by telling me why you're following me. "

"All you need to know is that I've been employed to keep you safe."

"You've already told me that. But why? Who's your employer?"

"I'm not at liberty to—"

"If you don't tell me who you are and what you're doing, I'll walk out into that storm." Dec stood so quickly, his head hit the tunnel roof. "I'm sure your employer wouldn't be so pleased if they found me tomorrow, buried alive." In that moment, he really did think he'd do it.

His manner must've been convincing enough because after a long silence, and a searching look, Rain stood. "You're not going to let this go, are you?"

Dec shook his head, while keeping his gaze steady, searching for the tell-tale flash of a knife blade.

She sighed, "Very well," and leaned against the tunnel wall, as though the very idea of having this conversation had already exhausted her before it had even started. "What do you want to know?"

Dec studied her face for signs of further resistance. "Okay..." he began. "What are you? Some kind of Northern spy?"

"I used to be a business consultant for the Northern government. It was a high stress job and I had problems with my health last year. So I left that job and elected to become a translator for the North-South migration boats. I'm good with languages."

That was true at least. "How does a 'business consultant' have the ability to fight off a police drone and pull knives from thin air?"

Rain's eyes narrowed. "Business consultants in the North do much more than just ... consult."

Dec returned her narrowed eyed look. "So you have special service training."

Rain didn't answer.

He switched his line of questioning. "Why are you following me?"

"I am under orders from my current employer, Angus Reid, Captain of The Cormorant—a merchant ship that transports Northerners to the South, and all kinds of consumer goods to the North."

"And why does this 'captain' have such an interest in my well-being?"

Rain shrugged. "I don't know."

Dec stalled, took a moment to study Rain's face to decide if she was lying. The more questions he asked, the more unlikely her story seemed. "Let me get this straight. You agreed to put your life on the line to protect me. You get torn up by a bot in the process, and you don't even think to question your captain's motives?"

"When Captain Reid decided he no longer needed my services as a translator, he put me on this assignment to keep you safe. It was that or send me back to the North where I'd be unemployed. I couldn't go back. So, I did what I needed to do."

Dec stared, suddenly understanding why she was pro 'lab rat'. She was a lab rat herself—a government drone, brainwashed to follow orders and not ask questions.

He took a deep breath to muster the courage to ask the question, "Fine. You were 'following orders'. What order where you following when you told me I was like you. That I was some kind of shadow walker."

Saying the word out loud again, gave it a dangerous edge, a feeling like he'd just turned a very sharp corner, and almost lost control of the vehicle.

Rain stiffened, and the light of her palm pod flared brighter as a pulse of heat from her skin flowed through it. After a long silence, she said, "I was never supposed to show myself to you. But when I got injured by that bot and you caught me out, I was so surprised that you could see me, I –" She shook her head. "It was a stupid mistake. I would never have made such a stupid mistake before ... And then, at the club, I made another mistake. I revealed myself to you again."

Show herself? Surprised he could see her? She was making it sound like she had some kind of ability to go unseen. Dec shook his head. It was obvious now—She was raving mad.

"You don't believe me, do you," Rain said, stepping forward. "Let me show—"

"Don't touch me," Dec said, retreating a few steps.

Rain closed the gap between them once more. "I want to train you, Declan."

The wind howled. A burnt smell, like sulphur, or ... something acrid filled his nostrils.

"I want to train you to do what I do."

He could walk out. He could take his chances. Find his palm pod. Call the police.

"To shadow people."

There was that word again. "I thought you said you were following orders." His voice sounded far away. As though it didn't belong to him. "Was training me to be a 'shadow walker' one of your orders?"

"No."

"Then your story doesn't make sense." He shook his head. "None of this makes any sense."

Rain took a deep breath, eyes widening and she spoke. "All I know is that I have a duty to the North, a duty to my captain, but also, a duty to our people." She went on before he could contest the 'our' part of that sentence. "Listen to me, Declan. Part of my job, back when I worked for the Northern government, was to train other ... consultants." The words were pouring out of her now, like a car going downhill without any brakes. "Consultants are sometimes required to collect valuable information from institutions where the information might not be ... freely available. It is in these situations that it can be very handy to be able to go unnoticed."

Dec frowned. The word 'consultant' clearly had a different meaning in Northern. To him, Rain's 'job' in the North was sounding more and more like special service work – shorthand for danger, lies, secrets and all things complicated. He didn't want anything to do with it.

Rain was still speaking. He forced himself to focus.

"Those who are extremely good at going unnoticed we call 'shadow walkers'—There aren't many of us. I was one of the shadowers to be trained under Kai, the creator of the art form."

She stepped up to him, looked him directly in the eye. She was so close, he could smell the soap on her skin. "And now I find it hard to ignore natural talent when I see it." She dropped her voice. "I have disobeyed many orders in telling you this. Now, I just hope my intuition was right. That you are the shadow walker I think you are."

Dec held back a sudden urge to snort. The term 'shadow walker' was starting to sound less intriguing and more like badly timed joke the more times it was repeated.

"You make it sound like 'shadow walking' is some mysterious supernatural power that I should be honoured to possess," he said. "Have you ever thought that maybe I'm just really good at being boring."

Rain didn't laugh. Her expression remained diamond-hard. "How did you diffuse Chook's anger back there on the street? You made yourself smaller. Not many people would've thought to do that, or could've pulled it off. And Lazar, he didn't realise you were sitting next to Tommy at the club until you made your presence known. You surprised him. That's why he wants to recruit you. He senses the shadow walker in you too."

Dec continued to shake his head. "You've caught the Desert Sickness."

"Tell me, have you gone unnoticed your whole life?" Rain went on. "Do people forget your name?"

Dec thought about Stanley, and how he'd referred to him as Derrick immediately after firing him. He thought about how, his whole life, he'd lived in the shadow of Tommy. But all these things didn't mean he had a special talent. It just meant he was forgettable. As Tommy had always said, he had a clash of strong features that served to cancel each other out.

Rain continued, "Your friend Teegan, she's a shadow walker too, but for different reasons. She has a keen brain for science—something a lot of shadow walkers tend to display. While you go unnoticed, she notices things others don't. She's observant. I find it more difficult to shadow you when she's around. I had to keep extra distance between us when you walked her to her apartment. I'd like to train her too..." she added in afterthought.

Dec was still shaking his head numbly. Teegan was observant. He had faded into obscurity all his life. But that didn't make them special.

"Still don't believe me?" She took his hands in hers, placed them on her shoulders and proceeded to fold herself against his body.

He was so shocked by the sudden intimacy, he just stood there and let it happen. He could feel taught muscle through her t-shirt and the smoothness of her skin.

"I shouldn't be telling you this. I certainly shouldn't be showing you this. But it might make you understand," she said.

All of a sudden, as though someone had turned off the hot water in a shower. Rain's body went as cold and as rigid as an ice statue.

Dec gasped and jumped back. "What the hell?"

"Why do you think lizards and snakes give people such a shock?" she said. Her words came out slurred and sluggish, like she'd held ice in her mouth for too long. "It has to do with stillness. They lower their body temperatures and become so still, they go unnoticed." She grasped his hands again. "Now, feel the difference."

Rain's digits went from icicle cold to straight-off-the-barbecue hot in the space of a few seconds. "Shit," he breathed, dropping her hands and wiping his sweaty palms on his jeans. But Rain hadn't finished. Something strange was happening to her body. While she was still standing in front of him, he was having trouble focusing on her face. It was as though she'd developed a blur around the edges. That, or his eyes were failing him in the dim light.

"What are you doing?" he said, rubbing his eyes and blinking rapidly. "How are you doing that?"

"If I heat my body so that my molecules oscillate fast, I can fade into any background. Think how the spokes of a wheel disappear."

As she spoke, her body blurred further, became transparent, like a reflection in a window. Then, as quickly as she'd faded, she came back into focus again. "Which is why I was so surprised you could see me in the cemetery. I was using my skill to stay out of sight and the only way you should have been out to see me was if you were a shadow walker too. And then in the tunnel to the club, when you went so cold and still that those people walking past to see either of us, that's when I knew for sure."

Dec stood stunned in silence. His mind riled against everything he'd just seen, and his eyes searched for some other explanation for the phenomena. A trick of the light, hidden mirrors, smoke screens, anything. He found nothing.

"What else can you do?" He didn't know where the question came from. It just slipped from his mouth.

"It depends where your natural talents lie. Some Shadow Walkers can access memories and knowledge stored in their minds for years. Some claim to be able to see into other people's thoughts. But the only person I've ever known to be able to sneak into someone else's mind and warp perception was Kai."

Read minds? Warp perception? He shuddered, remembering the voices he'd been hearing—the voices that had been giving him insight into into things he shouldn't know, shouldn't be hearing. What if the voices had something to do with 'shadow walking'?

He severed the thought at its root. If he accepted what Rain was saying, he would also have to accept that the workings of the world—time, space, matter—were not as he'd always known. And he wasn't ready to do that.

"You need to stay away from me," he warned.

"You still don't believe me?"

"I ..." he flailed for words. "I just want you to stay away. I don't want ... any of this." He was suddenly overwhelmed with the urge to get out of the cramped tunnel, to be anywhere but in the confined space with Rain, who wouldn't stop talking.

"You can't fight what you are, Declan. It will only get stronger. You either learn how to control your abilities, or they could start controlling you."

"I said, I don't want ... I don't want to hear it!" he blurted, tripping over his feet to put as much distance between them as possible. Soon, he was stumbling to get to the tunnel entrance before any more of her far-fetched ideas could get into his head.

His arms scraped the concrete walls. Rain's voice echoed in the space behind him. "Declan! You can't go out there. Declan!"

He pushed on through her words, bursting through the fluted entrance and into the swirling storm—suffocation seeming like a better option than standing there feeling like the ground had opened up, and he was falling through it. The world had never seemed so large and gaping. And he'd never felt so small. And all he wished was that he could just go back to that night at the cemetery and take a different route home, forget everything Rain had told him and shown him and never have to contemplate the laws of physics, of his own molecular biology again.

The sand whipped his skin—stinging, cutting, slicing fissures in his nerves. And when he breathed in, they stabbed him in the chest like thousands of splintered shards of glass.

He coughed and choked, was about to fall to his knees and tuck his head between his hands for respite, when he felt a jab to his neck and a heavy numbness descend over him like a wooden blanket.

Rain's voice, muffled by the wind, said in his ear. "I thought I could keep you out of trouble. I thought I could make you see. But I guess I was wrong. And now, you've given me no choice."