It always made me feel like a little child to wander these ancient underground halls.
The ones who built them had been so much taller than us. I have to reach over my head to touch the smooth ceramic panel that will open the door. The heat from my hand powers it somehow, makes the massive stone slab glide to the side, even now, millions of years after it was first built.
I step into the great public hall. We don’t know what they used it for, but I imagine it something like a public park. There are stone sculptures, at least that’s the way I see them, columns that stretch up to the dark ceiling where the light I’m carrying won’t reach, and carvings on the walls. This one is a low-relief landscape, I recognize the profile of the ridges that can be seen from the top of the shaft, but what’s different is that smooth area that must have been a lake or a sea. Now it is dry, empty. I think there might be things that resemble plants, or at least fragile mineral structures that have been swept away after millennia of sand and wind.
The next panel looks more familiar to me. It’s more mountains, but they’re covered with trees. A forest. I reach up to brush at a dusty patch of pine needles with my gloved hand. There are creatures here, abstract but identifiable. Something very much like a deer, but with an elephant’s snout. Another one like a porcupine with a club tail. A bird that stands taller than me, like an ostrich with an eagle’s beak.
It’s Earth, millions of years ago.
The next panel shows our entire globe, carved from the red sandstone in perfect detail. Oceans, continents, mountains. It’s amazing. This isn’t the only place where we’ve found it. They had an obsession with Earth, these creatures, whatever they were.
But for some reason, with all the depictions they made of their neighboring planet and the creatures that lived on it, they never left any images of themselves.
I climb up onto what might have been some kind of bench, that is if these creatures sat down. They left no remains of themselves, no bones, nothing. Some think they were gelatinous blobs, or maybe they were living rocks and their remains are lying around as rubble all over their tunnels here deep beneath the surface.
There’s a carving of mars too, small, up and to the left of Earth, their own world a mere afterthought in the stone mural.
And then I notice something new, something I haven’t seen before in all my studies of this place. There’s something on the wall between the two spheres. So small I overlooked it. I shine my light on it and it disappears. I need shadows to see it well. When I aim my beam just above it I can see it. There’s a whole row of them, marching like a line of ants between Mars and Earth.
These creatures, what if the left no remains because they all went away, and took everything that was part of themselves along? What if they all traveled to Earth?
What if they… they might be us.