This is how you died. You were worrying about something. Something that you probably thought was important. More important than the sky over your head and the strange things happening there. More important than the odd and scientifically implausible shapes the clouds were making.
But that was the only warning you would get before the ground cracked, and the horizon stretched like chewing gum torn between the pavement and a shoe. By then, self-interested creature that you are, you were already more worried about the ways your own body was betraying you. It too was distorting and spreading away, turning you into your own funhouse mirror reflection.
You felt all of it, every nerve being dragged away from every other, throughout your body, all at once. It was the most complete pain. You never saw it coming, you would never know why it happened, and after a couple of seconds it was over forever.
At least it was quick.
And so the first leg of the journey began.
It ended at a door.
The door was set into the base of an impossibly tall tower the shape of a sword blade and made out of a material that looked and felt like porcelain. The door itself was only visible as a circular pattern carved into the otherwise impermeable wall of the tower. It had been closed a long time.
In the length of time it took slime to become slime that could swim, slime that could crawl across the land and stand up and learn how to use tools and write stories and eat up their world and sit, staring into the unknowable sky as the last few elderly slime descendants died away and for everything they built to be eroded into dust while new slime took their place, the door stayed shut.
And then thirty-one days after you died, it opened. Pieces of the porcelain wall slid back and away. Blue light spilt out of the door and onto the ground around the tower, where it was broken by three shadows emerging into the world. A local would have seen three bipedal figures with grey and black skin, lit in places by the occasional bar of coloured electrical light. They each had two manipulating limbs and a shape like a stone tablet fastened to their backs. Where most creatures in this world kept a cluster of sensory organs, on top, and to the front, these things had a single golden orb.
The foremost creature reached up a limb and slid back its gilded dome, revealing a glass bowl that contained a far smaller, meatier looking head. Its face was mostly a pair of imposing cheekbones held together by an equally threatening chin. Placing a hand on each hip, he looked into the distance and intoned, "We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars."
Despite the gravitas of his words, his voice had the cheery confidence of someone explaining the rules of sports they only play in the expensive schools.
The figure to his right lifted her own visor, revealing a face just lined enough to look distinguished. It had graced the cover of a thousand industry publications, back home.
"Samson, did you spend the entire flight over here choosing that quote?" she asked.
Samson faced away from her as if inspecting some far horizon as he said, "I may have picked it out before we left."
Except, of course, there was no horizon. The ground and the sky simply faded out in the distance, leaving a white blur to separate the two. Directly in front of the astronauts was a grassy incline, coasting downwards onto flat green terrain that rolled out to the absent horizon, broken only by a single straight blue river bisecting the landscape.
The third astronaut opened his visor, revealing a face that looked oddly like Samson's. Except this face had jowls instead of cheekbones, and softer, more numerous chins.
"It's a bit disappointing isn't it?" he said.
Samson looked aghast. "Disappointing? How?"
"Well isn't this supposed to be the inside of a sphere? Shouldn't the horizon be all curving up into the distance while massive alien continents hang in the sky above us? I was expecting some serious majesty. This looks like the Norfolk Broads."
"Light gets dissipated through the atmosphere," the woman said. "If the atmosphere is anything like Earth's, we should be able to see a good twenty kilometres away. On Earth the horizon is… was barely a quarter of that distance. Here, if Rajita's sums are right, the ‘horizon' would be roughly a hundred and fifty times further away."
"Speaking of atmosphere," Samson said, referring to the smartphone mounted on the wrist of his suit. He frowned. "Hmm, the memory on here is very low. What are these large media files?"
"Rajita loaded the Star Wars trilogy onto our phones," said the other man. "It's the cinematic cuts. She said if the ship was destroyed she wanted them to live on."
Samson pulled a face to indicate he sympathised, if not entirely understood, then brought up a new app.
"I'm detecting a lot of nitrogen, a hefty chunk of oxygen, and a few traces of argon and carbon dioxide," he read. He looked up at the others, smiling as if he'd got a question right in a pub quiz. "I think we could breathe this."
"Assuming it's not teeming with flesh-eating bacteria," the other man said.
"Oh Connor, you worry too much," Samson said cheerily. "The chances are that any airborne bacteria on this planet would find your flesh quite unappetising!"
"And what are the chances of firing ourselves into space at random, only to arrive at a giant artificial sphere with a breathable atmosphere?" Connor asked.
"I hate to say it, but Connor's right," the woman agreed. "We're not jumping to any conclusions."
"Well of course not," Samson said, sounding only a little put out. "But one shouldn't underestimate the value of a hopeful outlook, especially in desperate times such as these. We could be looking at the new cradle of humanity!"
"Well we'd better be," Gordon said, taking a few steps out onto the alien meadow. "For their sake."
"What do you mean, for their sake?" Connor asked.
Gordon rolled her eyes. "Don't be obtuse. I mean that if we can't build some kind of survivable home on this world, we'll have to look elsewhere."
"Yeah but that's not actually on the table is it?" Connor said. "Samson? Tell Gordon that's not on the table."
"It's not," Samson said firmly, his face taking on a sterner expression.
"Oh relax the pair of you," Gordon said. "We still don't know there's anything actually alive here, and if there is, we don't know that it'll be sentient."
"So you think this is one of those naturally occurring Dyson Spheres?" Connor asked.
"They didn't respond to our signals. The docking mechanism was automated. The whole thing could be abandoned," Gordon said.
"There's this grass," Samson said, crouching down and brushing a hand along the floor. "The first non-terrestrial organism encountered by humankind. I'd say that's pretty momentous."
The blades of "grass" were more like four-leaf clovers, with five leaves, each perfectly hexagonal.
"Well while you open diplomatic channels, I'll get on with the actual work," Gordon said, turning her attention to her own phone and tapping a couple of icons.
There was a ringing inside her helmet, and then an agitated voice said "Yes?"
"Rajita, get the hab inflatable ready along with all the relevant instruments. We're coming back and then we're going to set up a base camp."
"Really?" Rajita gasped. "So not only do I miss out on the real, live Dyson Sphere, but I have to pack your camping stuff as well?"
"Is that a problem?" Gordon asked.
"No! Not at all. I'll just stop trying to understand the unfathomable workings of the prototype FTL engine and find you some tent pegs and a thermos…"
"Hey," Connor said. "Can anyone else see those boats?"
Gordon swiped Rajita's call off her phone, selected the long-distance lens and removed it from her wrist-mount to look into the distance. "Where?"
Connor pointed, and Samson lifted a hand over his eyes and followed the finger.
Far along the river, just before it faded to white, they could make out masts.
"We should go and meet them," Samson said.
"You're joking," Connor said, as Samson began walking in the direction of the boats. "This is an alien world. We don't know whether they're killer robots or acid-blooded dick monsters or… fucking Smurfs. We can't just waltz up and say ‘Hi!'"
"Your Before Weightwatchers photo is right," Gordon said. "We should study them at a distance. Figure out who we're dealing with before we go over and ask if they're on Facebook."
"They're travelling at a brisk walking pace," Samson said. "A brisk walking pace is the very fastest we can move up here. By the time we report back to the ship and come out again, they'll be beyond the, well, not the horizon, but they'll be gone and we've no way of knowing if this is a regular thoroughfare or an isolated back road. They might be the last people we ever see."
"You're being melodramatic," Gordon said.
"The interior surface of this sphere is five hundred and fifty million times that of Earth," Samson reminded her. "A trillion people could live here, and each have an area the size of Kazakhstan to themselves." He saw the way Gordon was looking at him. "Is something wrong?"
"Did you just work that out off the top of your head?" she asked.
"He did," Connor said. "That Kazakhstan thing's probably right too. He used to memorise the Atlas."
"Well, I was doing some very severe rounding, Kazakhstan is actually a little conservative, but then again, that assumes a totally habitable interior surface…" Samson began.
"All right!" Gordon gasped. She tapped her phone screen again. "Rajita, put that packing on hold. We're going to meet the neighbours."