At this depth, it’s hard to get any sense of time passing — or to know what time it actually is, for that matter. Down here, in the unfathomable darkness of the City, time seems to stretch and dilate; or on rare occasions, compress. When he bothers to look at his watch, sometimes only a few dozen minutes have gone by, even though he would have sworn it had been hours.

But no matter — it’s break time, and it’s long overdue. When his mind starts playing tricks on him, he can always count on his body to snap him back to reality. If only it could do so through means other than aches and sharp pains, that would be preferable, of course — but would he listen then? That’s far from certain.

Leaving behind the lab as it unfolds — an operation that will surely take a good half hour — Treyst goes to join the few workers who have decided to take a break. They’re sitting on blocks of stone, black as jet. One of them, exhausted and worn out, is already nodding off, while others are chatting, taking sips from their canteens, or chewing on energy bars. Even those who choose to stay awake look utterly spent and washed out.

The engineer sits down on his rolling chair and deactivates his Kelonic braces. Then he slouches back against the seat, trying to forget the pain that shoots from the base of his spine all the way up to his neck. He absentmindedly massages his battered legs to get the blood flowing, just like his doctor advised years ago… He’s done it religiously every day, like a mantra, even though he sometimes wonders what’s the point.

He rummages through the cooler and — pshht — pops open a can of soda, then gulps down half of it in just a few swigs. He sets it on his armrest before tilting his head back and letting out a long sigh.

Above him, the polyhedrons continue their immutable dance. Here, the perspectives are disorienting, all infinite loops, geometric patterns, and baffling vanishing points. He can’t look at them too long; their architecture is too insane, too aberrant. It’s a sensory challenge, quick to induce vertigo, to defy the laws of physics, and to assault reason itself.

The records say the City of Scholars is a remnant of the pre-Confluence era. But this architecture has nothing human about it. Over the centuries, it was probably devoured by the Tumult. Under its influence, it mutated. What remains is surely nothing more than an expression of the chaos the world has become. A curiosity, a deformation — like a cancer cell that consumes everything around it to reshape it in its own image… Of course, some traces of its former self remain: stairways, corridors, halls, and antechambers — but twisted, distorted into something almost unrecognizable.

During his studies, he learned about an artist from the World Before who liked to twist mathematics to create outlandish shapes. Though he can’t recall the name now, what he sees reminds him of those impossible constructions. Yes, everything here is an impossible construction… In the end, he misses the sky; even he, used to the twilight gloom of the Foundry, feels the lack.

Lifting his head, Treyst notices the workers haven’t even bothered to turn on their Kelon lamps. The diaphanous glow from the pumps is enough to light up the cavern they’re in — no need for any extra artifice.

Thanks to skill and a bit of luck, the Axiom energy specialists managed to convert the Kelonic cylinders to store this new substance, extracting a more or less stable energy yield. And though the process efficiency still needs work, it significantly eases the strain on current Kelon reserves, which have been at rock bottom since crossing the Storhvit.

He takes a square piece of the substance and drops it into his soda so it can dissolve. It’s already been a few weeks since the college of chemists discovered its invigorating and stimulating properties, to the point that all Axiom workers have gotten used to sprinkling it on their food or mixing it in their drinks.

‘Versatile stuff, isn’t it?’

Treyst blinks, seeing the Exalt Muna sitting on a crate, blowing on a steaming cup of tea. Spike curls up against them, yawning theatrically.

‘Sorry, I didn’t see you.’

‘No harm done,’ they reply with a smile.

‘What were you saying?’

‘I was referring to the substance you’re drilling. I was pointing out its versatility.’

The engineer nods, rubbing his eyes in an attempt to wake up a bit more. He takes another sip of soda before clearing his throat.

‘They say Hestia is even coming up with new recipes using it as an ingredient.’

Arjun toys with their beard, then looks down at their Alter Ego, who just sprawled out across their thigh. The creature looks fast asleep, like a child, even drooling on their pant leg. The Alterer doesn’t seem the least bit bothered.

‘They use it at the Farm as fertilizer; as fuel for your machines… and both the Lyra and the Yzmir consume it for its psychoactive effects,’ they say. ‘It makes sense the people of the City of Scholars made it the cornerstone of their society…’

Treyst frowns.

‘Sounds like there’s a warning hidden in that sentence.’

The Muna shrugs.

‘The botanists are close to confirming its harmlessness, from what I understand. I don’t think it’s dangerous in itself, even if for now, the Ordis urges everyone not to ingest it until official results are published. Just a precautionary principle, I imagine.’

‘But rumors are like weeds — hard to stamp out…’

‘No weed is inherently bad. But I think the City’s people came to rely on it far too much.’

Treyst cracks a smile.

‘Right, I forgot I was talking to a Muna.’

He glances over at the lab, which is nearly complete and operational.

‘I guess the lab will be ready soon. I imagine you’re here to have a workspace to study it?’, he says.

Arjun shakes their head.

‘I’ve already gathered all the information I needed here.’

Treyst raises his eyebrows. Before he can ask more, Arjun nods toward the wall behind the Axiom team. The engineer turns and sees a gigantic fresco climbing the wall, disappearing into the darkness above. He’d never paid much attention to the surroundings before, too focused on finding new substance tanks.

He squints to make out the bas-reliefs, whose lines have been worn by time. A great tree is depicted, covered in leaves and nestled between two twin peaks. Its roots seem to connect to a multi-tiered city down below the mountain.

‘The Cais Adarra?’

Arjun nods, their large earrings jingling.

‘I think I know what this substance is.’

Treyst’s eyes widen.

‘It’s the Sap of the world tree,’ Muna declares, with a hint of sorrow in their voice.

The engineer starts reviewing everything they know, right now. They’ve pumped gallons and gallons of this liquid without ever caring where it came from. They had to break sealed tanks, crack open cisterns, drill into reservoirs scattered throughout the sunken city’s foundations… without ever suspecting. He had assumed it was some manufactured, artificial, or processed product. But this new theory ticks all the boxes…

‘The City’s people channeled its Sap here to exploit it. But they pulled too hard, and the tree didn’t survive the treatment…’

An infinite sadness spreads across the Muna’s face.

‘I’m no historian like Leocardius Sree, but my theory makes sense, don’t you think? The City started to wither when the tree died. It declined because it had built everything on that supply of Sap… Thankfully, it’s not a mistake we can repeat.’

‘When the Sap finally dried up, the decline was inevitable… The stocks are finite. This is only a temporary reprieve for us. We can’t come to rely on it too much.’

Again, Arjun nods, stroking their Chimera’s head.

‘Just like we are with Kelon. And in Asgartha, the Spindle wouldn’t survive if it were drained like that. If anyone ever tried, the Muna would resist with all their strength…’

‘Sap…’

Treyst stands silent, stunned by what now feels like an obvious truth. The relics found in Caer Nilam, the substance residues… The people of the City of Scholars must have gone all the way there, before the cold overtook the region. When the climate was milder, they undoubtedly established a colony or an outpost there.

He watches Axiom prospectors maneuver the drill closer to the wall. The drill head begins to spin. It’s the first time a drilling operation is undertaken at this depth. But that’s not what’s on his mind right now.

Why had the inhabitants sealed such massive quantities of Sap? They could have used it — but they hadn’t. They went back up to the upper levels, abandoning all these reserves deep below… Higher up, in the tomb, there had been stories of many stelae, countless coffins found. Did they let themselves die?

The drill hits the black stone, filling the air with a deafening noise. Across from him, Arjun nods to him — a sign that the conversation has reached its end. Meanwhile, the lab is ready, and even the worker who was napping is now getting up, probably startled by the racket.

The Sap starts flowing from the wall, and workers rush forward with a pump to connect it to the opening. That’s when the ground starts to tremble, to rumble. All across the immense abyss, the black blocks start moving, accelerating, connecting to each other with an unusual frenzy.

‘What…’

He can’t even hear himself over the noise. Suddenly, through dozens of openings in the fabric of reality, Yzmir Initiates appear, surrounded by violet mists. They take positions, holding open portals to the surface behind them. Through one breach, a worm slithers into the cavity, its segments quivering as a dark-skinned woman with milky eyes guides it. But she’s not alone. Other Mages are with her: Gephyromancers, Phonomancers… The voices of the latter boom, drowning out the deafening roar…

‘Evacuate now! A Tumult Singularity is forming!’

Treyst gasps in shock and terror. Rossum sticks his head out of the lab and starts running toward him. It took only a fraction of a second for everything to spiral out of control, when just moments ago, they had been peacefully chatting with Arjun…

The engineer grabs for his Construct, but his fingers clamp onto the cryptex. He remembers he’s strapped to his chair and, in that brief hesitation, drops his cylinder to the ground. Like it or not, he activates his exoskeleton, gritting his teeth as it powers up.

Rossum rushes at him and slams into him, sending them both sprawling across the floor, just in time to avoid being crushed by a falling block of inert black stone.

His Chimera helps him get back up.

Must leave. Now.

He doesn’t need to be told twice and starts running as fast as his braces will allow. The engine smokes from the strain, while an Initiate gestures at him to hurry faster. As another block shatters on the ground, revealing its small aerolith core, Treyst staggers again, forced to drop to one knee. He turns, dazed and panicked, and sees the world tree fresco cracking apart.

From all the walls, tongues of darkness erupt, leaping from the fissures to converge on the drill mired in a pool of Sap. No — not tongues. Voracious arms, with clawed fingers…

Deep below, something is hungry.