This post was inspired by a prompt in the Worldbuilding Community, Worldbuilding Prompt #672 - Number patterns.
Enjoy !
Image created by AI in Nightcafe Studio
"What do you make of it, Zhavan ?"
They were staring at what looked like some kind of stone door. It wasn't what they had expected to find. The expedition had been on Opirion VI for six months, digging away at mounds of dirt and ruins half a million years old. They knew there had been a civilisation here, and that it was long dead. But that was all they knew; they had no clue what they looked like, how they lived, and how they had died.
Most of the cities they had excavated had been just piles of rocks and dust. Half a million years of erosion will do that. The planet itself was lifeless now, but it still had wind, rain and frost.
Finally they had tried digging in this ruin. It was slightly different; a deep canyon with rubble suggesting there had once been a settlement here. When they entered a cave mouth on one side of the canyon, they'd found a pile of rocks inside. Heaped up as if deliberately rather than just as the result of a rock fall.
Behind the heap of rocks was a door.
It was set in a stone frame, and made of something which looked like sandstone. But their instruments had indicated it was far denser, with interlocking molecules providing diamond-like strength. The surface was studded with projecting bobbles of rock,
Chief Science Officer Zhavan shrugged a little before responding to his expedition leader, Infomancer Baran.
"It's a door, Sir, but I can't see how to operate it. There is no obvious lock or handle, just all these rocky protrusions. It's incredibly worn, but compared to everything else we've found on Opirion VI it is like new. It does give us a clue, however; whoever these people were, they used doors about the same size as ours, which suggests they may have been our kind of size.""
As he spoke, he ran his hand over the door, admiring the effort it must have taken to create something so beautiful, unfathomable and just durable.
Both scientists were utterly shocked when his hand passed over one of the rock protrusions and it moved.
It clicked inward by maybe a centimetre. But that was enough. The door sloughed off the dust of ages as it slid haltingly downward into a previously hidden channel.
With the door open, they saw it led to a short corridor, maybe twenty feet long. At it's end was another door, identical to the first but in far better condition. It hadn't been exposed to half a million years of weathering, it had been protected by the first door.
Ignoring scientific protocol in their excitement, both men strode forward to it. Zhavan pressed a protrusion in the same place as on the first door. Nothing happened. He sighed in a deflated manner.
"Well I guess that was too good to be true. I wonder which bobble opens this one ?"
Baran studied the door and it's protrusions intently.
"Zhavan, look closely. Can you see how one or two of them are more worn than the rest ? Try those."
Now it was pointed out, Zhavan realised it was true. The surfaces on two of them were worn smooth as if from regular use. He pressed them one after the other. Nothing happened. Then he tried pressing them both together, one with each hand. This door slid down into it's secret resting place smoothly and silently, opening up another identical corridor and door.
This door needed two hands to press worn protrusions, and it was only when he leaned in and pressed his forehead against a third that the door slid smoothly down.
It revealed another corridor, and another almost identical door. When they studied the rock blobs, they saw that this time, five were worn. It took both of them to press all the bobbles simultaneously.
Another corridor was revealed, and yet another door. Seven worn bobbles.
"Have you ever played Twister, Zhavan ?" Baran asked with a grin as they used hands, foreheads and one foot to open the door.
"No sir, but I think we might have a problem. It's Prime Numbers. I can guarantee this next door will have eleven worn ones, and the one after that thirteen."
"Damn, you're right. I wonder how many appendages this species had ? There has to be a limit !"
The next door did indeed have eleven worn protrusions. It took a lot of twisting and falling over before they were able to work out a combination of hands, feet, foreheads, elbows and knees that would open all of them simultaneously.
The seventh door had thirteen worn bobbles, as Zhavan had predicted. Their hearts began to sink; even if they could work out how to get this door open, they'd need help to open subsequent ones. How many doors were there ? Would there be a point where they just couldn't fit any more people in to help press all the bobbles they needed to ?
"Look ! Look Sir !" Zhavan pointed to the corridor walls. All the other corridors had had plain walls. For the first time, this one didn't. There were highly stylised images embossed onto it.
The first showed a large circle and ten small ones in a row; an obvious map of the Opirion system.
The second was similar, but had another circle up near the ceiling. Smaller, filled in. Arcs radiated out from it, small segments of circles each of about thirty degrees of the diameter of a whole circle. Arc after arc, parallel to each other, radiating out from the dark circle like waves. When they eventually reached the system map, the planets they touched were filled in, too. Including the sixth one.
Baran nodded. "By the Emperor, it's clear now. A nearby supernova. The radiation from one close enough would sterilise any planet it hit. Poor people, they never stood a chance."
It took half an hour to work out how to press thirteen bobbles, but they stuck with it, knowing that this was the final door.
They were right. As the door slid down, their powerful headband lamps revealed a huge chamber. It was rectangular in shape, and as far as the light carried they could see row after row of crystalline tubes. Each one was the right size to hold a person, and each had some kind of control console next to it.
It was clear this was where the last survivors had entombed themselves, going into stasis or deep sleep, hoping to rebuild their world after it had been scoured by the supernova's radiation. But something hadn't worked; maybe they had relied upon a wakeful survivor to reverse the process and reawaken them, or maybe a computer had been programmed to do it. Whatever it was hadn't happened.
At the bottom of each cylinder was a film of red-brown dust. The result of five thousand centuries of decay.
Baran and Zhavan would never know how many appendages this race had posessed.