Pilgrimage
On one of the oldest of the Gem controlled planets, there is a service corridor.
It is a very, very old service corridor, found near what was once the planet's surface, before extensive mining made such a description essentially meaningless. It is long, cramped, and winding, a place rarely visited by anyone except service Gems. If you need to deliver something quickly and discreetly— be it a message or something more physical— there are few faster ways to do so. Most Gems who take the route do not dawdle; it is hardly a pleasant place, and tardiness is not tolerated.
Sometimes, though. Sometimes, a Pearl will slow. Younger Pearls, usually.
The hallway is spartan and nearly barren, with plain walls. The corridor is ancient. There are still brackets on the walls marking where torches once hung, before it was upgraded and modern lighting was installed. There are old stone cabinets, too, which were once used for storage. They're all empty now, so no one knows what they once must have contained— scrolls, perhaps, or some other form of long-outdated technology. There's nothing inside them, now.
Mostly nothing.
Sometimes a Pearl will slow. She'll look quickly down the hall, in both directions, straining for the sound of distant footsteps. She must be certain that she is alone. Then she'll duck down, open one of the abandoned storage cabinets, and look inside.
They're empty. Empty, aside from the marks scratched in the stone walls.
There's hundreds of them. Thousands. None of the Pearls know how many, exactly. No one has ever had enough of a chance to stop and count. They're packed in tight, filling up every spare surface. Meter after meter of cabinet is filled with with tally marks. At one end of the hallway, they are old and faded, but at the other, the marks are sharp and fresh.
There's one other thing in the cabinet. A knife.
Nobody knows where it comes from. Nobody would ever ask. All the Pearls know is that it is there, and that whenever it gets worn down, somehow, a new one will eventually appear to replace it.
Every Pearl who arrives on this planet hears of this place. Every Pearl on this planet seeks it out, at least once in their life. A pilgrimage. Every Pearl takes the knife, holds it in their hand, and carves a small line or simple mark in the wall. Simple, wordless. But still, it says:
I was here.
Hundreds, thousands, countless of Pearls, throughout the millennia, all saying the same thing.
I was here.
The Pearl will make her mark, put the knife down, close the cabinet door. She will trot off, poised and polite, and return to her duty. She may never come back. Whatever her fate, her mark will remain, for other Pearls to see.
I was here.