When the elevator doors dinged, but didn't slide open, Christopher's first thought was of Albert Einstein.
Einstein's famous thought-experiment on general relativity states that a person standing inside an elevator would have no way of knowing whether they - and the elevator - were at rest under Earth's natural gravitational pull, or in fact hurtling through outer space, accelerating upwards at nearly 10 metres per second squared.
More precisely, Christopher wondered if the doors would eventually open onto nothing and he'd be sucked into the vast expanse of space.
For a few seconds, he let the thought experiment play out. In the 10 seconds he'd thought he was sliding at roughly-constant speed up from his basement office to the ground floor of the building, it was entirely possible he'd been instead moving much faster. He'd been distracted - nodding goodbye to each of the tech assistants - when he first hit the Close-Door button, so he might've missed an irregular intial acceleration.
In fact, if he'd been moving at massively increased speed for those seconds, he could be miles from the Earth's surface by now. Gravity's pull on the elevator around him would start to lose its strength, and potentially he could even be picking up speed.
A harsh BZZ startled Christopher from his thoughts. The 'Alert' light on the lift's console was flashing red.
Another BZZZZ. A tinny voice exploded from the speaker unit. "Hey, is anyone in there?"
Christopher hit the microphone button and leant close. "Uh, yeah, I am. Is something wrong?"
"Buddy, you've been at a standstill just off the main lobby for 5 minutes. You think we're just keeping you there for the fun of it?"
"No - sorry, course not. Sorry."
The voice huffed. "Well, we hope to have you out of there ASAP but we don't exactly know what's gone wrong so it might not be speedy. Power outage or something. You got any dinner plans you were rushing off to?"
He ate dinner at exactly 7.35pm every night, but doubted that was what he was being asked. "Not plans to meet anyone, no."
"Good. Hang tight, we've got a repair team coming in about an hour. Think happy thoughts."
There was another BZZZ, and the man inside the speaker was gone.
Christopher wondered how far radio transmissions could travel into space. Theoretically, of course, radio-waves have infinite range -- that's how we can detect traces of the Big Bang echoing around the universe. But given that he lived in a world where transatlantic phone-calls were still sketchy, he somehow doubted that humanity's broadcasts into the wider cosmos were quite as successful. Still, as long as he was still somewhere inside the solar system, he supposed that a sound file like the one he'd just heard could've been sent from back home.
Back home felt a long way away, now. He thought of his flat, with its alphabetised bookcases, calming brown sofa and familiar-if-not-beloved noisy neighbours. He gave the microphone button another poke.
"Hello?" No response. He considered addressing his queries to Houston or Ground Control, but figured the guy on the other end probably wouldn't find him funny. "Is there any way someone could get to my flat and water my plants for me, please?"
BZZZZ. "Water your plants? How long do you think you're going to be stuck in there for? Jeez."
Christopher took that as a no, then.
The voice crackled back over the line. "Look, we're trying our best. Repair team on their way in a few hours."
Last time, the repairmen had been only an hour away. Either the repairmen were getting further away, or Christopher and his elevator were.
Christopher paced a few small laps of the elevator, before he started to feel dizzy and took a seat on the polished-metal floor. It was warm to the touch, which startled him a little, but then he supposed he had no idea how hot or cold the floor usually was.
The walls, when he put his palms against them, felt uncomfortably warm too. In fact, the whole elevator was heating up.
Every day, Christopher left his office at 5.45pm. It was late August, so he assumed (although since he'd been underground all afternoon, he couldn't be sure) that it would've still been light outside. In its ascent, if the elevator had gone anywhere other than straight up, he would've felt the change in direction.
In conclusion: he had to be rushing closer and closer to the Sun.
He pulled off his jumper.
It'd been at least ten minutes since he'd last had contact from the buzzer-man. When he came to think of it, he hadn't recognised the guy's voice. He knew the whole security team by name -- he'd worked in the same building for 12 years, and always said hello to each person in the lobby as he came through, including on the security desk. But the voice hadn't been Jim or Tina or Tariq.
Christopher had even been asked to come in for the graveyard shift for a midnight software release a few months back, and the night security guard was a lady named Robin, so it couldn't have been her, either.
He weighed his options for a second, before hitting the speaker button again.
"Hey, Mission Control? Any updates for me?"
He allowed himself a weak smile while he waited for the reply. BZZZ. There it was.
"What? What are you talking about?"
Was that a note of panic Christopher could hear in the voice, as if they'd been rumbled? He backtracked, slightly.
"Never mind, just a joke." He snorted, but the voice stayed silent. "Look, I've been thinking, and I can't work out who you are from your voice -- Jim, is that you?"
Christopher waited, but no clarification came. "Oh. Are you new?"
"Nah, been here a couple of years now."
"Are you usually on nights?"
"Um, nope? Most people don't notice the guys behind the security desk day-to-day, don't worry about it."
Most people didn't, but Christopher always had. He knew the names of all the cashiers in his local supermarket, all of his neighbours (even though had only ever spoken to one of them) and each of the 58 other employees with desks in the basement. There was no way he wouldn't have noticed this guy, unless was lying about ever having been there.
Christopher put his ear to the speaker. Was there a chance the sound quality had been getting better this whole time? Instead of travelling away from the source of this voice transmission from home, he started to consider the possibility that the signal was getting clearer, because he was in fact getting closer to it.
BZZZ. "You still there, man?"
Wincing, Christopher hit the microphone button. "Yup, still here. What's the situation on the repair guys?"
"Should be arriving in the next 5 minutes."
It was getting steadily hotter. Christopher tugged off his shoes and then, on second thoughts, his socks too, and stacked them with his jumper in the corner.
Christopher had no way of knowing how fast he was travelling, but when a sudden juddering crash shook the elevator, he supposed that he had probably come to a stop.
If, as he suspected, he'd been accelerating through space for the past hour, the deceleration of landing on firm ground would've crushed his little aluminium elevator, with him inside it. And yet he seemed to be intact. The impact had to have been cushioned by some external help. Which begged the questions, where was he and who had helped him?
He must've made a noise in his shock, because there was a hammering on the roof, and then a muffled voice shouted down to him:
"Oops, didn't mean to startle you, mate! We're just the repair team, hope to have you out of there ASAP!"
A screeching, scraping sound followed, and a hatch opened up in the ceiling. Into the gap, a sweaty face appeared.
"Oh. Hello," Christopher said, at a loss for anything better to say than I come in peace. Belatedly, he added, "It's good to meet you!"
The man who claimed to be a repairman waved a thumbs-up through the hatch without looking. He clanged around for a bit in the machinery on top of the elevator, and finally, the face appeared again.
"I've got no idea how you've stayed so calm down there for so long!" he grinned, "There's a unit up here that's been overheating for the past hour, aren't you absolutely roasting?!"
Christopher gestured at his bare feet and fogged-up glasses and gave a weak shrug.
Within minutes, the man on the roof yelled out "There you go!" and there was a pneumatic whoooosh as the doors slid open.
From the safety of the elevator, he peered around outside. Wherever he had ended up, it had certainly been designed meticulously to look like the ground floor lobby of the office he'd left earlier that evening. The reception desk was in the same place, the floor-to-ceiling windows had a similar dark tint, and the brash swirls in the carpet were almost the right colours.
Over at the reception desk, three men he didn't recognise were babbling into phones, and a steady flow of employees were scanning in through the electric gates to bustle towards their desks.
Strange, he thought, to have employees scanning into the building at nearly 7pm. But he supposed you couldn't expect anyone to get every detail right.
Christopher shouted goodbye up to the repairman, whose name he had never caught, and stepped out into this strange new world.