They say there's a documentary out there. It's titled by most as "the mammoth hunter". Very few people have seen it, very few people are allowed to. It's the oldest documentary made on earth.
Alien anthropologists, these strange mantis like organisms, came to earth around when homosapiens were just making their way into Europe, to film a documentary on the local culture. They were there for a broader research project but the only thing they left was the documentary.
They weren't there to do anything special. They didn't share any technology with us. Didn't build any great monuments or start any civilizations. They really just wanted to learn more about our culture. It took them awhile to get our ansestors to be ok with interacting with them, but eventually they did, and spent a few years with one tribe.
The documentary is amazing from a modern lense. There is footage of tribesmen, the ansestors of modern humanity, living their lives. There's film of a huntsman taking down a wooly rino, of women hiding from now long dead Saber tooth tigers. And there's footage of them just existing, singing songs, playing with their children, showing the documentary crew how they make stone tools or how they make their art. One of the longest scenes is just of one of them telling on of their people's stories, thousands of years before any of their descendents will have a chance to write a story in stone.
And they were freindly with the crew. Whatever culture was making the documentary they didn't seem like the type to want to colonize or exploit them, or at least that wasn't the goal of the scientists, even if others on their planet would have. They just wanted to learn. And though the tribesmen were scared of them at first, eventually they befriended eachother, and knew eachothers names. The humans let them into their homes, and let them eat their food, and partake in their rituals.
From what we know the second expedition had to leave early. That's actually why we have a copy of the documentary, because they left it there. From scattered notes and things some of the scientists said in the film, we know it's quite possible that the aliens were on the brink of some sort of war on their homeworlds. Many of the scientists seemed to fear that weapons of mass destruction would be used, and reset their civilization to something as primitive as what ours was at the time. Mabye that's part why they thought to make the documentary when they did. A lot of people think they wanted to come back, but they just couldn't.
We don't know where they are now, but we've grown a lot since we last saw that civilization, let's hope we get a chance to see them again, even if our roles have to be reversed, let's hope we can still be freinds after so long.