Not for the first time I wonder if, all those years ago, Dr. Deng might have had any idea how magnificently cliché it would feel to approach the boundary of another mind. The space is cavernous and midnight blue; I am a small, shiny capsule drawn at a measured pace towards the very center of a swirling vortex, a portal-like discontinuity, deep emerald flecked with yellow on the other side. It's impossible to describe almost anything about loop-lock in a satisfying way; but for this in particular, I refer you to Kuayu Yingxiong, a sci-fi blockbuster that came out around when Deng was, like, seventeen.

The portal bulges behind me as I cross. Gossamer strands in my wake pulse with telemetry. The Bridge isn't using very much memory — Deng’s terse, infuriating Rust was handwritten for an earlier age — and most of my mind is actually just idling. I play a little trick with my attention: I zoom back outwards so the drama of the probe and the vortex feels like something happening with my index finger. Back in again, so it fills my attention, the rest of my mind a yawning void. Here, thick clouds of deep green tiles surround me, flashing with voxelized thunderclaps of computation. The unknowable thoughts of another mind in loop-lock. 

A boring day in the clinic involves finding the right reproducible inversion from the catalog — packed with pre-wound logical guts — and firing them into my patients’ minds from soberspace. This is not one of these days. The Deng bridge has fashioned me into something similar, a tightly-packed capsule. I make my way inwards in my diving-bell shape, curious if Mallochi can feel me yet.

For a neikonaut accustomed to the wild freedom of solo loop-lock, the Bridge would be a disconcerting, even frighteningly constricted experience. And, well, it is. Inside the diving-bell the tiles are mine and mine alone. But they — that is, I — run up quickly against unyielding walls that separate my patient from myself. Briefly I attempt to think thoughts — that is, attempt computations — that run out of tiles and painfully segfault against its pricky-static pixel-hot boundary. Here, the Bridge works tick-by-tick to maintain separation between this little bubble of me and the rest of my patient’s mind. It takes a few deep breaths to find my footing in tighter loops and simpler heuristics. 

When the capsule starts to feel forgiving, even a little roomy, I push for the boundary again, this time with calibrated effort instead of flailing panic. All I do for a long while is attune myself to the static until I start to pick out Mallochi’s unfamiliar rhythms. It's all wrong! How can he even — but with a practiced burst of intention, I give myself over to the alien logic of his tiles. It's nauseating, then merely uncomfortable...and so on. All I really have to do is sit with it, feeling the Bridge ebb and flow, feeling the boundary blur. Mallochi’s internal logic becomes familiar, then amusing, then even a little endearing, and soon I can play it out for myself. There's phase lag, and plenty of little bursts of static where I get it wrong, but mostly there's a surface where it's hard to say where I end and he begins.

{{What — impossible — in the fuck did you — ??}}

What comes rippling into the capsule could almost be a fragment of my own thoughts.

{{You’re doing great.}} I keep it all double-stuffed with reassurance and devoid of double-negatives, knowing how much will be lost in translation between us. {{You're doing great. We can take as long as you need to make sure you're comfortable. Best thing you can do is relax. The Bridge will keep us both safe.}}

He doesn’t respond, not exactly, but waves rock my diving-bell this way and that as he takes stock of his mind. Harrumphs tidally as he finds some critical subsystems disabled.

{{Why can’t — — ?}}

{{I put you in diagnostics mode,}} I reply, getting the gist. {{Guardrails, for both our sakes.}}

{{ — tickles — — hurts }}

{{It will hurt less if you allow my tiles to seep into yours. This happens naturally. You may notice that you've become more comfortable with my patterns of thought.}}

When they realize this, they always tense up. I brace for the jolt. Some forays with the Bridge fail right here when patients can't get the knack of intentionally sharing tiles, but in a few hundred ticks I feel a loosening. An invitation. I'm impressed, but to say so would only trip him up.

{{The Bridge will prevent me from growing too large, too quickly, within your mind.}}

{{That — — not worried — — all day. Feel way — — than down — }}

{{There is nothing to worry about. I will keep my movement slow and careful. All you’ve gotta do is watch the fireworks.}}

Slow and careful is hardly just for his benefit; I need to move gingerly or I could be zeroed out by a stray allocator. I focus on squeezing myself through dormant blocks of memory, fractal-catacombs that morph just gradually enough for me to keep up. These free blocks are a treasure trove of neikotic debris. Halite-crystal chunks of old order books, abandoned state machines bubbling into nondeterminism, even a glimpse of a stray alpha-beta pruner whipping past like a tarantula-boomerang. He’s way overdue for a cleaning. But these are minor headaches, maybe blurred vision...

{{When is the last time you went in for —}} And just then, a bare fucking tumbleweed of pointers sails by and flays off part of the diving-bell’s hull with its tiny velcro hooks. The diving-bell’s bare six-pack of instruments inform me that somewhere down there, my body has bitten its own tongue. {{ — for an inversion?}} And then another one rolls past, and another one, these two all but successfully dodged with a stomach-turning drop. {{Wait, are you doing this?}}

{{Doing — — ?}}

{{This. Look. Look at the way it’s moving.}} All of the debris blowing listlessly through his mind is heading in the same direction. As though pulled towards a drain. I fashion a tiny glider from the tiles around me, a paper-crane thing, and watch as it too is yanked electrostatically in a direction that’s beginning to feel like inwards. {{What’s going on in there?}}

But here at the outskirts of his own mind, Mallochi is either too cowardly or too sensible to know. {{Won’t — listen —  reason — —}} he warns me. Offers a somewhat sullen farewell as I chart my course inward, following my paper-crane as it tumbles through the roiling and discretized fog.

You can learn a lot about a neikonaut from the debris that sticks around in their head. Now, as so much of the stuff bobs along with me in the same current, there’s no need to pretend I’m not intrigued. I sample each piece, serializing bits and bobs up the increasingly narrow strands of self leading back out the Bridge. Yep, he’s a trader. Or was, once. The rest of my mind responds on a long delay as I point myself around like a periscope. 

That’s a bit of the contract API for the parallel yuan. Standard stuff.

That’s a black-market approximation of Paracoin’s L2 forex flow lattice.

That’s...uh, don’t get any closer to that.

In flashes where the clouds part I glimpse sky-high minaret callstacks, ornately geometric mandala-trees, buzzing-thrumming event pumps, all in glossy candy-coated brilliance. It's one thing to watch this from the clinic's control bank, to get tantalizing snatches of order flashing across a flat monitor of tiles. To be here, to have been here — it wakes me up sometimes, breath ragged, sweating through the sheets.

And I know I’m getting closer, closer to something, because Mallochi’s discomfort is becoming pain.

{{Causal — dimensionality — fairly — modifications —}}

He’s trying to explain what he did to himself. Though I try to relay this up the wire, there’s little use: down in soberspace it will be a mere inkling, a hunch at best. But faithfully, clinically, I note what I hear.

{{ — — don’t — — — proprietary }}

Oh, yes?. Like I want to save a slice of this for myself? As a little treat for later?

The further I press, the more tortured his computation becomes. As this trickle of trash reveals itself to be a mere tributary, his tiles form stuttering loops, malformed log-log trees, whole subsystems deadlocked by a broken semaphore (I flip that bit as I pass, and feel tingling waves of secondhand relief.)

{{Please — — can still —}}

Some parts of him are less welcoming. They insist I'm wasting my time. The tiles here make me queasy, flashing with bouncing timeouts and mismatched checksums. 

{{Can handle — — —}}

The rest is drowned out by pain. Whole ribbons of debris are converging, accreting, swirling in the center of his mind: it all crumples and breaks down, the unsyncopated cracking of countless digital bones, chrysalis-hot meshes dissolved, liquefied, homogenized into a raw golden medium that crackles and flares, swirls widdershins around a white-hot stellarium drain. It looks pretty bad.

It would be nice, in fact, to be merely looking at it. But that’s not how things work in loop-lock. Already too late. I strain against its massive logical gravity...

{{I wouldn’t go in there,}} Mallochi warns me.

...but I’m just gelatinous bycatch now, jammed between two spokeless, half-melted event-flywheels, straining, trapped inside this thing, pinned down tidally and slammed again and again by decomposing debris as I reach its eerie golden bellmouth, the thing which should not be here, the hole in his fucking mind. My flailing is getting perfunctory. I hold something like my breath as it pulls me into its maw...

...which narrows into an irregular fibonacci mesh, into a nest of tiny tubules, networked nodules, thumping with liquefied psychic waste. It seems designed to destroy any sense of scale. What was just tiny is now ten times larger, arterial and cavernous, which is either some tilespace trick I never learned, or it’s consuming Mallochi at an ever faster rate. And all the while the diving-bell is painfully riding the walls, beginning to slough off at the edges, no longer held together by any external logic, more and more just a purple-and-white bolus of panic, small and scared and lost and lost and lost.

If it wanted to, it would have digested me by now. It wants something else. Solidifies, this far in, and begins to open up. Walnut-ridged, half-hollow, fjordstruck. The walls crawl with with tiny interlocking spirals, sinister zigzags, half-signifying, golden-meaning and onyx-madness.

And they’re reflective. I brush a nearby surface and it brushes back in the same way, reaching out with a root system of tiny arc-whips to sting, to punish — no. To measure me. In its millions of facets I glimpse the diving-bell’s insectoid hull. It’s the most baffling thing. In loop-lock, things don't just reflect light. The reflection is something that has to be computed, ray-traced. It takes tiles, cycles, time and energy to do this. Why bother?

If: black, gold, roots, spirals. 

Then: eject. 

The recognition is pure pattern recognition. The reaction is pure motion. The core of the diving-bell throbs and sends the signal up the wire: get me out of here. Before it does what I know it can do. Of course we wonder what it looks like up close. All the way down here, in loop-lock, in this form, there’s not enough of me to remember it by name. Right now out there there is China and there is this and one is bringing the other to its knees. Eject.

Why am I not ejecting.

Because the wire is gone. The diving-bell is untethered. The Deng Bridge can no longer see me in here, can no longer bend the rules of loop-lock to keep me safe. I am a separate being in a foreign mind, hermetically sealed inside tradespace weaponry that no Mallochi in no world should ever have, now eating his mind from the inside out. My only remaining purpose is inversion.

{{I know what this is,}} I posit to Mallochi. {{It will help me treat you if you can tell me where you got it.}}

I don’t expect him to answer. He keep a quivering, stilted silence in here, because movement brings the root system, the arc-whips, dense electrical knots of them bursting radially forth to innervate his tiles against his will.

The bread and butter of modern financial modeling: take something complex, strip it to its essence, clean lines and simple strokes. Understand it. Predict it. That’s what this thing’s for, what this spherical reaction-chamber does, to anything you put inside it  Air-gapped and quarantined, it would be incredibly useful to a trader. But it’s escaped quarantine, and is now trying to measure and understand its host. Along all its reflective surfaces, it’s computing a simpler version of Mallochi’s mind, inside of his own mind. The pain must be unbearable.

In the interlocking shadow and gold, I brush another brief glimpse of the diving-bell’s reflection. The concentric zebra-glyphs flashing lightning-quick across its surface. That's me, I realize, feeling strange. That's really me, right there, on its inner surface.

Outer surface?

I try to recall, to retrace. Suppose it all depends on whether, back there, I’d taken a left or a right or an up or a down. But nevermind.The problem is this: for anything to survive the roiling chaos of a mind on DMT, it has to be self-duplicating, constantly reasserting itself — the loop in loop-lock. I fashion the diving-bell into something dangerous, slashing and hacking at the roots of the Sieve, but they're back within a few ticks. The part contains the whole, brilliantly, dangerously. Sometimes the solution is slashing faster, hacking harder. I've gotten myself out of any number of jams this way, but here I am too small. Dizzy and disoriented, a dozen diving-bells watching back from a dozen reflective walls. I let it tickle me for a few ticks.

What are its roots doing?

Their branching is fractal, self-similar. A small wedge in their logic seems like a promising place to start. I trace a single root though dozens of branches, but I never really find a tip. Its silken strands fray into the tile noise in to observe Mallochi’s fine structure. I let some into the diving-bell for examination.

Their microstructure is wild. Insane. I can hardly imagine a neikonaut keeping track of it. The way it intercepts the fundamental update-rules of his tiles is not quite random, not quite logical. Or perhaps the logic exists in some higher dimension, with just enough repetition in its shadow to keep me guessing in here. With each tick, gnarled pointers reattaches to Mallochi’s memory. Seem to anticipate its changes.

In fact, it almost seems like...

A flash of insight, maybe from watching carefully, maybe from up the wire. I act. I'm injecting a burst of fibrous taps into the tiny knot, already doing battle now with the Sieve's finest roots, trying to interfere, to untangle them. I surround whole swathes of its spindles, detaching and garbage-collecting them, a game of Go played tick-by-tick. I can barely keep up as the battlefield grows, the logic becomes too subtle, it surrounds me now — but in a hundred ticks my tingly wildfire has wiped out a volume of the root system the size of the diving-bell, and it grows back slowly enough to watch.

This could be the inversion. I reach in and try again —

{{ — — STOP! — — }}

Mallochi roars this, unmistakably, into the diving-bell on a wave of raw fear. Now I see what I was missing.

{{ STOP! — STOP! — — }}

The debris isn't holding on to Mallochi at all. He’s holding on, for dear life, to the debris.

{{It's okay. It's okay! I need you to please calm down.}}

{{ — — KILL — BOTH — — ! }}

{{Do you feel this?}} I struggle to stay calm against his high tide of viscous panic, directing his attention to a little velcro-knot of pointers where he grasps at the roots. I magnify this structure, flatten it across the diving-bell, playing it on a loop for him to observe. 

{{Do you see what you’re doing? Do you think you could let go?}}

A long nothing. Now the hair-thin microtubules around me are decoupling, slowly at first and then alarmingly fast. But then, with a whip-crack of tiles, they snap back into place.

{{ NO. No. No — — can't. No. }}

{{Why not?}}

Four hundred ticks go by. I can sense tiles shuffling, Mallochi collecting his own thoughts. His response, when it comes, is little more than a magnification of his own silence. Subtle tile-flash draws my attention to the diving-bells reflected all over the cavernous walls. He says nothing, but his meaning is perfectly clear. What are the odds, he asks, that you’re the real one? What are the odds that I am? The roots are all-permeating, all-measuring. My insides and outs. Nothing mere about these reflections: in the solid half of the debris, a toy model of this same conversation is playing out. Me: the diving bell, only even smaller and simpler. Mallochi: himself, only more panicked and confused. 

Or…?

No heart, no throat, but something very much like all that. A downward semiprime spiral of dread. My patient watching my every move. I press myself up against a tubule wall, against the diving-bell reflected therein, and flash a question across my surface tiles. {{What are you like in there. What are you feeling.}} And what else could I possibly expect in return? Yet I linger there. Knowing that if it’s feeling anything at all, it’s exactly this: this rising panic, this just-what-do-I-really-remember? I press myself against my reflection for a long time. Maybe I’m looking for a telltale lack, a certain simplicity. Or maybe I’m daring it to move first.

{{Right,}} I finally tell Mallochi. {{Enough of this. One of two things is true.}}

{{One: you’re not the reflection. You let go, the debris disappears, you remain. You survive this.}}

{{Two: you are the reflection. You let go, you’re gone, yeah? But you never actually let go. You’re just the thing in the mirror. You never really had the choice.}}

Yeah, of course I know about the third thing.

Judging by his silence, so does he. But...

{{Okay — — try — just — }}

I give him time enough to change his mind, and a few ticks besides. Then...

{{We'll both do it,}} I tell him, expanding the diving-bell, allowing my fringes to succumb to his logic, allowing it to overtake me, offering just the faintest nudges to his tile-paths. His — our — grip on the debris begins to loosen.

{{If I'm wrong, we'll go together,}} I insist. He insists. No — the distinction is there, but only just...I’m the willpower, and he’s the detailed grasp of our fine structure. He courses through me in waves, and I feel ourselves untangling tilewise from the root system. I'm growing larger and vaguer now, the diving-bell just a faint membrane between us, worming manyways through the winding alleyways and thoroughfares of the debris...

The nature of our fear unfurls, revealed in the unmeshing of billions of pointers. The tantalizing, sickening sense that we could be deciding from behind the mirror. Because...because...discretized flashes of soberspace memories course through our tiles now — standing in front of mirrors, in front of Mirror Sea displays, for too long too high too late, watching for something, daring it to happen, it can be true if you believe it...

The un-meshing has reached a critical point. Couldn't stop it if we wanted to. With what's left of the diving-bell I move to encircle the debris, to carry back its shriveled remains. I'm not leaving without my prize. We cut loose a particularly thick segment of roots. {{See? Nothing to worry about,}} we lie to ourselves.

And everything goes black.

Maybe I expected it to be more gradual.

But this is how it always goes in here. I don't know if there's sound in loop-lock, exactly, but there's an overwhelming roar of nothingness as the final pointer breaks; for a few ticks we're just decaying chunks of stray tile in a cache. Somewhere on the outside of the mirror, the real diving-bell executes a long-planned, highly-optimized maneuver: it serializes a model of the debris and fires it hard in the direction I came from. I go through the same motions in here. Jerky, spidery death throes. Now I am the debris, empty, hollow, thoughtless...just...just.

On the far side of the Bridge, though, the rest of me has been waiting.

A large, jagged polyhedron of tiles, coal-black and glossy yellow, comes floating lazily through the portal. I send it straight to the voxelite printer. Once I would stand vigil for the diving-bell, hoping against hope for the strangest kind of reunion; now I slam the Deng Bridge shut with no hesitation. Time to go home. How? Right. Thumbs.

Right thumb. I slam the big dumb button. The drip stops, the tiles become larger, slower, simpler, I can feel my whole being flattened into a single plane of pixelated color, reaching for combinators, lenses, callbacks, pointers, registers and feeling only blind, dumb, organic chaos. Remembering on hard-won instinct not to panic here, it's okay, you'll be back.

I can hear the printer running already, constructing a voxelite shard, a death mask of Mallochi’s debris projected downward into three dimensions. A memento. A desk toy. And at YINS, something a little like contraband. I can never anticipate what these will look like, and yet I'm never, ever surprised. I'm blinking. I'm biting hard on my tongue, my whole mouth tastes like iron. The UTMS bed is slick with sweat. I like to give myself a long count of ten before facing the real world.

“Stop!” Muffled by the scanner hood, I hear Yao step away from the control bank, insisting something about the waiver and dead if they catch you. A reproachful grunt, the clatter of glass, unathletic squeaks of two pairs of trainers on linoleum. By the time my finger finds the release, Mallochi is gone gone, just the beaded curtain swinging in his wake. Yao strides back my way, panting, still wielding the glass lid from a jar of cotton swabs. He looks humiliated. “I tried to stop him.”

“I heard ya, bud.”

“That was...tell me that was what I think it was.”

In the scuffle, our patient let the following items fall from his pack: a pack of Hi-Chew candies, a tube of antibiotic cream, a quadcopter remote, a nightclub wristband, and three fake N-1 licenses bearing several slight variations on his name. The holographic foil is dead-on, but it’s peeling at the edges. I don’t answer Yao until the printer is done, and I snap the voxelite model off the bed, singeing my fingers.

The debris is glossy and jet black, but held to the light it reveals generous veins of gold. It has a complex, hooky texture, which makes it hard for my eyes to pass smoothly across it. “I mean, it’s gotta be, right?”

It’s many-petaled lapel pins glimpsed through the tinted-out windows of veetles that rarely touch asphalt. Oblique references on earnings calls, in diplomatic cables leaked from Zhongnanhai, basically nothing to go on, but the Sunflower Sieve is all that a certain kind of YINS student will never shut up about. 

“Yeah. Yeah.” Yao’s hyped now. “We’ve gotta tell someone. But wait, no. If we tell YINS then someone will tell Haojie and then they’ll go after him and then he’ll go after us. So we need to — oh, come on, let me look.”

An Indonesian billionaire has laid half his fortune down as bounty on it. Supposedly it’s the future not just of tradespace warfare, but of everything, an omni-tool used for now only to tighten the screws against Beijing. In the meantime’s it’s been the specter haunting campus for the last half of summer, threatening to make everyone’s dissertation irrelevant. What I did, just now — that’s more medicine than science. There’s no paper in me for it. But quietly, they say, it’s been chewing through the Big Three’s best neikonauts. Of course I want to know for sure if I just faced off against the Sunflower Sieve and won.

“Maybe there’s some kind of anonymous tip line...” Yao muses, looming broadly over my shoulder.

I palm the debris, play my fingers along its grooves. I know I’ve seen these shapes before. That’s the thing about loop-lock, of course. The deja-vu will crush you if you let it. You will hit rock bottom in the gap between in there and out here. But this is more than that. The color and texture is new, but the shape, the flow, the silhouette. The way it claws out for more of itself.

“Mona?”

My palm snaps shut around it. “Let’s clean up.”

I let myself think the thought, once, clearly. And then sixteen months of conditioning kicks in, I nest blurry matryoshka domes around it. I put the thought in a box, in another box, in a part of my mind that I must not look at or all quadratic hell will break loose. I know I’ve seen these shapes before.

I just won’t say where.