I power down the last computer at the registration desk. The screen clicks off.

Friday nights at Riverside Surgical Center always end like this. Just me, alone in the building; wandering the halls, making sure everything is powered off, closed and packed up for the weekend. It's my favorite part of being the sole IT support specialist here. When everyone else rushes out, I get these perfect moments alone. With the equipment.

The hum of the building's air handling system becomes noticeable as I cross the deserted, silent lobby. My footsteps click against the polished vinyl flooring. I walk to the entrance, diligently checking that the automatic door is locked closed. It is. I’ll lock it again when I leave, but tonight I don’t want any unexpected visitors.

I turn and begin my rounds through the facility. The surgical center’s manager thinks I'm dedicated. In reality, I'm obsessed.

Medical technology has been my special interest since I was a teenager. While other kids collected posters of rock bands, I hoarded medical supply catalogs. By eighteen, I could name every component of an anesthesia machine and knew the admin passwords to a handful of patient monitors. The job here at Riverside isn't high-paying, but it gives me access to a playground of sophisticated equipment that nobody outside the medical profession would get to touch.

The pre-operative area is my first stop. Six curtained bays line the wall, each containing a stretcher with accompanying vital signs monitor. I walk slowly, making sure each monitor (a Phillips model I know well) is powered down. When in use, their screens show blood pressure, SPo2 and pulse rates. They’re seldom used with ECG leads in pre-op. I notice things like that. I’ve always been into the small details.

Regardless, they’re all dark now. The monitoring system's central station sits at the nurse's desk. They’ve already turned it off.

I walk into one of the bays, and push an IV pole out of my way. Mounted on the pole is an infusion pump, its digital display dark. I check the bay's cabinets, making sure the stock of IV catheters, saline flushes, and adhesive dressings are orderly. I don’t really have to do this; it’s a med tech’s job, but… I want to.

As I check the next one, I pocket a couple of alcohol prep pads. Then a few pairs of purple nitrile gloves from the wall dispenser. Nothing that would be missed. I've been collecting “supplies” for months this way. I tell myself I’m building my own personal medical kit for home, but I know I just like having this stuff.

The staff lounge is next. There’s not really anything in here that I need to power off; we’d all be in trouble if I shut the refrigerator down. Nothing seems out of place here. It was one of the nurse’s birthdays today, and there are cake crumbs on the table. I skipped the party, but I helpfully wipe them up. There’s a box of masks by the door, though, and I take one, adding it to my scrub pockets. My heart rate increases slightly at the thought of what I'm planning later, but for now, I just turn out the breakroom’s lights.

Moving on with my patrol, I enter the post-anesthesia room; the PACU. This is more or less a mirror of pre-op, but with closer monitoring. The ECG traces on the monitors get used here. Eight recovery bays face a central nurse's station where the staff can observe all of the waking patients at once. Like pre-op, I verify each is powered down, and catch one that the nurses missed.

I pass through the automatic double doors that separate the PACU from the main corridor. My pulse quickens as I approach my actual destination tonight: the surgical suites. Riverside has three operating rooms; more than average for the facility’s relatively small throughput. Each is specialized for different types of procedures.

OR 1 is the largest, equipped for general surgery. Its boom-mounted equipment arms hang suspended from the ceiling in standby mode. The room lights are off, and the surgical lights on articulating arms are stowed neatly against the ceiling. I stare through the door for a moment, then move on.

I walk to OR 2, which is set up primarily for orthopedic procedures. The C-arm x-ray unit is parked in the corner, draped with a protective cover. Riverside sees a lot of broken arms, ACLs that need repair, and the like, but I’ve never been that interested in medical carpentry. Everything looks alright here, so I move on again.

Finally, I reach OR 3. It’s the smallest of the three rooms, sometimes used for endoscopies, but also for gynecological and urological procedures. This one has always held a special fascination for me, for reasons I leave unexamined for now. The operating table here is equipped with integrated leg stirrups, really more like giant yellow boots, that can be positioned at various angles. The table itself is computerized with both foot pedals and a remote. It can be easily moved to nearly any position, which is why I’ve chosen it for tonight.

I hesitate at the doorway, my heart pounding. The room, like the others, is dark and still. My hand finds the light switch, and I flip it. The room lights and overhead surgical lights come on at once, uncomfortably bright. I let my eyes adjust for a moment, then I step inside and let the door swing shut behind me.

This is my plan. This is the reason I’m so helpful on Friday nights.

I move purposefully. The anesthesia workstations here are slightly older than I might find in an academic center, and frankly, that’s what I want. It still has physical knobs that I could twist, instead of a touchscreen. I approach it; running my fingers along its smooth surface. I think, just for a second, how embarrassed I’d be if someone saw me basically petting the machine. But I’m alone. That’s the point.

On the far side of the operating room is an entire wall of supplies. Opening a cabinet, I locate the components I need. A disposable breathing circuit, nicely packaged with a filter and a gas sampling line. A pair of rebreathing bags, and an adult-sized anesthesia mask. In another cabinet, I find a four-point head harness, designed to keep the mask securely in place during procedures. I lay these items out methodically on the anesthesia machine's work surface.

Next, from a different cabinet I retrieve a pulse oximeter sensor, and a blood pressure cuff. I return to the anesthesia workstation, and connect both to their respective ports on the machine. Even if I didn’t know where they went, the plugs are colored and fit only in the right place. It just takes a few seconds, despite my slightly trembling hands. I think about getting ECG pads; the machine is already setup for 5-lead, but I decide it’ll be too awkward to manage the wires.

I connect the breathing circuit to the outlet and inlets on the anesthesia machine, carefully attaching the corrugated tubing and the rebreathing bag. The mask will go at the end of the circuit, but for now, I just slightly inflate the plastic seal around the mask’s rim with a syringe, then I lay it down on top of the machine

I press the power button on the anesthesia machine, listening to the startup sequence of beeps and watching as the ventilator performs its self-test. When it’s done, I perform a machine check, following the same protocol the anesthesiologists use each morning. I verify that oxygen flows properly from the wall outlet through the machine's pipelines. The backup oxygen cylinder shows pressure on its gauge. The nitrous tank is open and full. I check the carbon dioxide absorbent canister; it's fresh, the granules still white instead of the purple that would indicate it’s all used up. This is good, because I’m not actually sure which cabinet would hold a replacement, and I don’t want to search.

It takes a few minutes, but the checks complete cleanly. The rebreathing bag inflates and deflates properly and everything holds pressure. I slip the mask onto the business-end of the anesthesia circuit, pressing it in place firmly.

This machine, I note, has two vaporizers on it, purple and yellow, iso and sevo. I don’t plan to use these, but I see that the liquid level indicator on the sevoflurane shows about a quarter full. I’m intrigued but volatiles are far too dangerous to mess around with.

With the electronic foot pedals, I adjust the operating table to its lowest height setting and position it at a slight incline, so I can sit comfortably on it. The table’s dual armboards easily fold down, out of the way completely. I’m relieved to see the stirrups are likewise folded down; I'll have no need for those tonight. When I’m done, the operating table resembles a very expensive, very black chaise lounge.

I wheel the anesthesia machine closer to the operating table, careful not to pull the gas supply hoses too far. With some effort, and a couple more change to the operating table’s pitch, I position it where I can just about reach the machine’s controls, while seated on the table.

I shimmy to the center of my operating-table-made-chair. I smooth out the sleeve of my left arm and wrap the blood pressure cuff around my own bicep. It’s awkward. I struggle with the Velcro, trying to get the cuff closed in the right place on my arm, and to tighten it appropriately. After a few attempts, though, I get it close enough. The pulse oximeter clip goes easily onto my right index finger, and rhythmic beeping starts to track my heartbeat. I reach to the anesthesia machine, and using my middle finger to put the button, start the cuff. Within seconds, the monitor displays my vital signs: heart rate 92, blood pressure 138/84, oxygen saturation 99%. My elevated heart rate and blood pressure doesn't surprise me. I've been fantasizing about this whole thing for months.

I reach out to the machine’s controls and set the oxygen flow rate to 6 liters per minute. The flow meter's ball rises in its chamber, indicating the gas is flowing as expected. The room fills with a quiet hiss.

I pick up the mask, and I feel a momentary hesitation. What I'm about to do crosses a line, from a special interest to something more dangerous and much more against the rules. But the temptation is too strong to resist. I've come this far, after all.

I bring the mask to my face, feeling the soft plastic seal against my skin. It's cool at first, but quickly warms against my face. I take a deep breath, smelling the significant plastic scent of the new breathing circuit and mask. The oxygen fills my lungs.

I pickup the black head harness, and, with a little more awkwardness, I secure the mask to my face, tightening the straps until it stays sealed tightly even when I’m not holding it.

My breathing sounds loud inside the mask. For a few moments, I watch the rebreathing bag inflate and deflate rhythmically with each breath I take. I watch my oxygen saturation maintain at 99% on the monitor. Everything is working perfectly. It’s time to take the next step.

I reach for oxygen flow knob again. This time, it twist down… and twist the nitrous oxide tap open. I know how the flowmeters work, and set the balls to a roughly 33% nitrous oxide flow. I take a deep, deliberate breath through the mask, and the effects begin almost immediately. A pleasant warmth spreads through my limbs. I hold the breath for a second, then deliberately take another very big breath. My fingertips tingle with a curious numbness. By the third breath, a buzzing sensation starts at the base of my skull, radiating upwards into my head. I’m surprised, and more than a little bit pleased, at how fast I’m feeling the nitrous. I've read about this feeling countless times in medical literature and online, but experiencing it firsthand is amazing; both the physical sensation and the forbidden nature of what I'm doing. I want more. I turn the oxygen down slightly again, and the nitrous up.

I lean back onto the operating table, letting my arms fall to my sides, and take in more of the gas as I relax.

The room maintains its sharp edges and clinical brightness, but my perception of it begins to shift. The surgical lights above me seem more intense, their glow extending just a bit beyond their actual boundaries. The rhythmic sound of the gas flowing through the circuit becomes hypnotic. My breathing is less intentional now, but even so, I’m still breathing slowly and deeply. The rebreathing bag inflates and deflates and I enjoy watching it for a couple of minutes. Inhale, exhale. Inflating, deflating.

I check the monitors with slightly unfocused eyes. My heart rate has decreased to 84 beats per minute; it’s still elevated from my normal resting rate but lower than before. My oxygen saturation remains good. The blood pressure reading cycles automatically every five minutes. The cuff tightens around my arm before letting go with a soft hiss: 125/76. The beep of my heartbeat has slowed.

I laugh, muffled by the mask. I watch the rebreathing bag some more.

The blood pressure cuff cycles again; time is stretching, I’ve floated here five minutes already, and dissociated without realizing it. There’s a clock on the OR wall, and I watch it for a minute. It moves simultaneously slowly and fast. I smile. I’m happy, and… I want more.

I decide to increase the concentration. My movements are deliberate, almost ceremonial, as I pull myself upright, then reach out to adjust the flowmeters. I’m already around 50%, and I want a bit more. I twist the nitrous upwards, nearly as high as it’ll go. I can tell the difference almost immediately.

The buzzing in my head intensifies, becoming a gentle vibration that extends through my entire body. The boundaries between myself and the room begin to blur. The operating table beneath me seems to become softer, much softer, as if I might sink through it if I relaxed completely. I don't, though; I still have the presence of mind to lower myself back onto the table gently, instead of falling off.

I let myself drift again. I think about the nurses and surgeons who work in this room, wielding their instruments, controlling life and consciousness with practiced hands. Now I'm doing the same, in a way. This thought seems somehow hilarious and profound. I don’t start laughing but I’m pretty close. Before I know it, the blood pressure cuff is cycling again.

I raise my hands in front of my face, fascinated by how distant and blurry they seem. I wiggle my fingers, watching the movement with detached curiosity. There's a delay between my intention and the action, as if I'm connected to a video game on a bad internet connection. I slide my palm along the cool surface of the operating table, the sensation of touch seems simultaneously intensified and muted.

A new thought surfaces through the haze of nitrous oxide: what would sevoflurane feel like? I know that nitrous, at normal pressure, can’t actually knock anyone out. But sevo, at even at moderate concentrations, induces unconsciousness within minutes. I don’t want that. Even while intoxicated, I clearly understand the consequences of gassing myself to far. But my understanding of MAC is that at lower concentrations, like, say, 1% or 2%, people my age will generally remain awake. At least for a little while.

I could try it. Just a little.

I know it’s dangerous, but the idea is irresistible.

I sit up again, and reach for the anesthesia machine, my movements a lot less coordinated now, through the nitrous fog. First, I turn down the nitrous oxide flow to zero, allowing pure oxygen to clear my system for a moment. I take several deep breaths, feeling some of the fuzziness recede. My thoughts sharpen enough for me to recognize the recklessness of what I'm about to do, but not enough to stop me.

I turn the yellow vaporizer dial just a bit, turning it to 1%, then to 2%. Enough to taste it, to feel its initial effects for real. I’m not feeling tentative now, like I was with the nitrous, even though I know I’ll need to quickly turn it off. I breath all the way out, and the sevo begins to flow.

The first breath is still mostly oxygen, and I let myself settle back onto the table. When I take the second breath, though, a distinctly sweet smell fills the mask. It smells chemical, like a harsh cleanser, but… not unpleasant. I don’t feel anything. I take another careful breath, then another. Only then, does the effect hit me.

A heavy warmth spreads through my body, like someone’s thrown a weighted blanket over me. Another breath, and I start to feel distinctly tired. The nitrous made me feel fuzzy primarily, this is making me feel drowsy.

I try to breath normally, and the edges of my vision begin to blur, the periphery darkening slightly. It’s as if a camera’s vignette effect has been applied to my eyesight. The beeping heartbeat sound in the room seems to recede, becoming muffled and distant. It’s much more intense than the nitrous, and much more intense than I expected. I understand, in a moment, how stupid I’ve been. I need to turn the gas back off.

I sit up, trying to reach the machine, and it feels like I’m moving through syrup. My intention to move my hand doesn’t match my muscles exactly; the same effect as the Nitrous but more severe. The machine seems farther away than it was a moment ago. I reach for the vaporizer dial, and my own hand seems disconnected, as if it’s not mine.

Before I can reach the dial, another hand appears in my peripheral vision. A hand that is, for sure, not mine.

I try to turn my head, movements sluggish, brain struggling to process this unexpected development. A figure in blue appears, standing beside me, and grabs my wrist, pulling it back from the vaporizer.

"What have we here?" a female voice says. "Someone's been playing with toys they shouldn't touch." The words have a British accent, and seem to echo strangely in my ears.

I start to speak, but the mask is still harnessed to my face. I try to reach up to remove it, but the woman grabs my other wrist, too.

In the harsh surgical lighting, I see it’s a woman in blue scrubs, a surgical cap covering reddish hair, bright eyes above a white surgical mask. It's a nurse, but in my disoriented state, I can't immediately identify which one. Panic cuts through the chemical haze. I wasn't supposed to be discovered. No one should be here. The staff all left. I made sure of it.

I’m not sure what to do. I try to stand, to pull away, but my reactions are dulled by the anesthetics already in my system. The sevoflurane continues to flow; I still haven't turned it off, and each rapid, frightened breath draws more of the agent into my bloodstream.

"Turn it off," I manage to say, my voice muffled by the mask. "Let go of me!"

"I don't think so," the nurse replies. I feel myself being pushed backwards, down onto the diagonal operating table. "You've set everything up so nicely. It would be a shame to stop now."

I'm larger than her, stronger under normal circumstances, but the sevoflurane has substantially undermined my coordination. She pushes me down easily. But I’m not done yet; I turn sharply, trying to break her grip, and succeed in pulling one arm free. I reach for the mask, intending to tear it away, but she’s fast, or I’m slow. She blocks my hand, catching my wrist again.

"Oh no, you don't," she says, her voice hard. "Keep that mask on."

Fear spikes through me. Each breath is drawing more sevo into my system. I thrash, but the head harness keeps the mask firmly in place despite my movements, and the continuing supply of anesthetic makes my fight increasingly clumsy.

The nurse adjusts her grip, pinning one of my arms under her body, while reaching for something on the anesthesia machine I’ve placed so conveniently close by. To my horror, I see her turn the sevoflurane vaporizer not down, but up. I can’t see where she’s set it, but I know anywhere above 3% will rapidly render me unconscious.

"No!" I shout this time, the word completely intelligible even through the mask. I buck upward, pressing my legs against the table, trying to get up. For a moment, I think I might break free. The pulse oximeter rips free from my finger, setting off a high-pitched alarm from the monitor.

I’m able to slide my right arm free of the tangle of limbs, and I grasp at the mask, fingers scrabbling at the head harness, but they just… won’t… get it… My fingers don’t work right.

The nurse recovers quickly, catching my free wrist a third time, and forcing it down. She swings one leg over me, straddling my chest and fully jumping on the table. Before I know it, she’s on top of me. She’s using her weight to pin me down. Her face is close to mine now. It’s aggressively intimate, her blue eyes intense above her mask.

"Don't struggle, love" she says, her voice simultaneously soothing and menacing. "You'll only make it worse for yourself."

With her full weight on top of me, my movements grow increasingly fruitless. Even if she wasn’t on top of me, the feeling of heaviness, the feeling that started after my first few breaths, is much stronger now. Each time I try to push her off, the physical exertion forces me to breathe harder, deeper, pulling more sevoflurane into my system. I realize that the more I fight, the faster the anesthetic is taking hold.

My vision begins to waver, the straight lines of the room twisting and bending. The nurse's face above me seems to split and rejoin, her mask and eyes turning blurry and confusing. I blink rapidly, trying to clear my head, but my eyelids are harder and harder to open each time I do. It doesn’t help at all.

"You're quite strong," she comments, sounding slightly out of breath, but in control. "But the sevo is stronger, love. Always wins in the end."

My strength is failing rapidly now. My arms feel impossibly heavy, as if I’ve been tied down with giant elastic bands. I still struggle, but my movements are feeble, uncoordinated. I’m losing.

The room begins to spin in slow, nauseating circles. The lights overhead multiply, separating into a rainbow of colors. My hearing seems more affected now too: the nurse's voice echoes strangely, as if coming from multiple directions at once. The alarm from the disconnected sensor sounds distant, as if I’m underwater.

I'm aware of my breathing becoming slower, deeper.

"That's right," the nurse says, her voice drifting to me through layers of distortion. "Stop fighting now. You're doing so well."

I watch the nurse as she climbs off of me, but somehow, her weight seems to stay. She maintains her grip on my wrists for another few seconds, but my arms have gone limp. She releases them cautiously, maybe prepared to restrain me again if I’m faking it, but I am very much not faking it.

I can barely lift them now. My eyelids feel impossibly heavy. I force them open only with tremendous effort, trying to focus on her face, but my vision is degraded, or my brain won’t control my eyes. I can’t tell which. I try to think of something to say, but I can’t.

"Good," she says, her tone shifting to something almost… sexual. "You're submitting beautifully now."

I hear the sound of electric motors as she repositions the table, I feel myself tipping backwards. She’s straightening my legs, raising the table, returning it to a flat configuration. She gently places my arms at my sides. I want to resist but can only manage the weakest of movements.

The nurse moves to the anesthesia machine, adjusting something I can't quite see. The sevoflurane concentration, I realize distantly. She's increasing it again. The time I breath, the gas rushes in forcefully, making me breath fully and deeply. She’s squeezing the rebreathing bag.

"Just close your eyes and drift off now," she orders, her voice seeming to come from very far away. "It’s dreamland for you."

My eyelids flutter. No amount of effort can keep them open. I realize with a distant sort of horror that I'm about to lose consciousness. I make one final, feeble attempt to sit up, to roll off the table, but my muscles refuse to cooperate.

A curious peace begins to replace my fear. The inevitability of going under becomes almost comforting. I can no longer remember why I was fighting so hard against this feeling. I’m so incredibly tired and I just want to sleep.

"Perfect," she murmurs, watching as my resistance fades completely. "That's exactly right. Let it happen." I hear her, but I don’t understand.

I can’t see the nurses’s face anymore, as spinning blackness rushes in from the edges of my vision. Yet somehow, I know she's smiling as she watches me fall down to oblivion. The world clicks off.