If you’ve been to the peak of Mount Chiliad, Grand Theft Auto V’s highest mountain, you’ll have seen this bizarre mural in the cable car station. But what does it mean? This is the question inspiring thousands of GTA players to scour Rockstar’s huge world for clues, in an attempt to solve a mystery that may not even exist.

It’s been dubbed the Chiliad Mystery, and its dedicated subreddit is one of my favourite places on the internet. The genius of this mystery, whether intentional or not, is that Rockstar have turned a large section of their playerbase into precisely the kind of tinfoil hat-wearing UFO nuts they mock in their games.

And it’s amazing. Reading some of the theories, I can’t help but be impressed. They range from the plausible to the absurd, and they’re all hugely entertaining to read. People are convinced there’s more to GTA’s endgame than the UFOs that hover in certain areas of the map once you’ve reached 100% completion.

Some people say the trail is leading to a jetpack. After all, the icon on the bottom-right of the mural does look a bit like one. Others say there are flyable spaceships waiting to be discovered. But whatever the theory, these passionate investigators have been united by one shared belief: that the truth is out there.

You can read more about the UFOs and the first steps of the investigation here, but I thought it would be interesting to round up some of the latest theories. Thanks to the PC version and the efforts of modders, several discoveries have been made in the game’s files that have brought the community back to life.

Rockstar haven’t said a thing about the UFOs, the mural, or anything else. Presumably because they know their silence only adds to the compelling nature of the mystery. Or maybe because there is no mystery. Some people think it’s a dead end, but others are convinced there’s an incredible secret buried deep in the game, behind cryptic alien glyphs and Illuminati symbols. I want to believe.

You can get inside the UFOs

In this massive thread, trainwreck42o has gone through the game’s code to look for clues: specifically the script attached to the UFOs.

“There are interiors which can load, and the script which loads them requires the player not to be injured and for a certain global variable to be either -1 or 999.” they explain. “If we are uninjured and have the global variable set correctly when viewing the UFO, we will know the interiors are being loaded.”

“If we assume we are able to meet those requirements, the final step is to uncover the warp points which will take us from Mount Chiliad into these interiors.”

But what’s the mystery variable? No one has managed to find out—yet. Some people think this reference to the UFO interior is just the ship from Michael’s drug trip (which people have actually found), but others think it could trigger a UFO abduction sequence, or a chance to pilot the UFOs for yourself.

The Maze Bank fountain is the ‘egg’

There’s a pattern on the fountain outside the Maze Bank building that, according to some, looks like the crack on the egg pictured in the mural. But UFO hunter Huge_Dabs thinks there’s more to it than that.

“I’ve studied sacred geometry before and I can NOT believe I didn’t catch this.” they explain here. “Notice the egg of life and the fountain are identical! This means it’s an egg, just not the kind we were looking for. The crack lets us know it’s the one from the mural!”

I wouldn't say they were identical, but it's an interesting—if far-fetched—idea. Would Rockstar really be this cryptic? If so, that might explain why it's taken so long for the mystery to be solved.

There’s a message hidden in the Space Docker’s horn

The Space Docker is a special vehicle received as a reward for collecting all 50 spaceship parts. It’s a dune buggy with a B-movie sci-fi design, and the horn makes a series of bizarre noises when activated.

So, naturally, someone decided to run the audio through a spectrograph analyser. “This horn matches the alien language seen written in the alien camp.” says DidSomebodySayFIB, referring to a chain of symbols found here.

Musicians have hidden images in audio before, notably Aphex Twin, so could there be something to this theory? Or is it just a coincidence?

If you want to join the quest to solve this puzzle (if there even is one) you can download a 100% GTA V save file here. And if you find anything, don’t forget to post the results on r/chiliadmystery—but read the FAQ first.