Now that I have your attention …

This is not a theory that I will hold a crusade for. However, I find it interesting. Most theories, most thoughts that get circulation now, are either old, old news or so outlandish as to be unbelievable.

This one, however, feels solid.

I do believe that by and large the UT fandom has been operating under some false assumptions about Gaster. The general understanding is that Gaster, after falling into his ‘creation,’ was retroactively erased from the Undertale universe. But, while the evidence at surface value might seem to imply that (it certainly fooled me), a closer examination calls that into doubt.

Let’s talk for a moment about why people believe that Gaster has been erased. To be fair, this belief has some pretty good circumstantial grounds! There are a few key pieces of evidence that people think of when referring to this. First: Goner Kid. Second, the Gaster Follower who holds a piece of Gaster in his hands.

Let’s talk about the follower first.

Here, we learn about how Gaster was ‘scattered across time and space.’ What this means is not made clear, but it seems quite bad. The way he mentions ‘time’ seems to imply that Gaster could have been spread not only into the future, but into the past … Still, would you not say that jumping to ‘therefore he is erased’ is a leap? No, it’s not. Because of what we hear from Goner Kid.

Here. Here is the key to where people draw the ‘erased’ comparison. Both Goner Kid and this Follower are gray ‘Fun’ events, which seem to be linked in some way to Gaster. The ‘another world’ talk is eerily similar to the phrasing that the River Person uses. “The man from another world.” A phrasing that is replicated again to refer to ‘the man who speaks in hands.’

But that perspective has its flaws. We learn about Gaster from some of the other ‘followers.’ Spread across Hotland, they tell us his story … And in the process, raise very important questions about our mysterious skeleton friend.

Here is an important question: if Gaster was retroactively ‘deleted’ from the universe, why does the Core exist? Many theorists hypothesize that his research may have been the building blocks upon which Alphys built in her study of the SOUL and DETERMINATION, and point to him as the most likely source of the mysterious DT extractor blueprints. Sometimes, the suggestion will be made that sans or PAPYRUS brought the blueprints with them and gave them to Alphys, but in that case, how do you explain the Core?

The Core is Gaster’s creation. The creation that killed him? Maybe, maybe not, but it is surely his work, built with his own two hands, with the ingenuity of his own mind. It shouldn’t be here. It shouldn’t be here. And yet it is. And yet the blueprints are. What determines when something has temporal inertia or not? And why does everything Gaster made seem to still exist?

And while we’re on that subject, it’s interesting that this stranger talks about how it took Asgore a long time to find a new royal scientist. That’s strange. Really strange. And it’s a point that is repeated by the other followers, too. It took me a while to figure out why this was strange.

All this talk about how Asgore must have waited so long for someone to come who met Gaster’s quality of excellence, that the reason Alphys was picked now was because who could possibly follow the brilliant doctor Gaster?

This would have only been a problem if Gaster was never retconned. If Gaster was retconned, someone else would have been there to build the core. Someone else would have had to step into the hole Gaster left to make the world where ‘everything is exactly the same.’ Someone would have to fill that void.

What’s more, it’s implied that the reason that Asgore waits is because he remembers Gaster. How does that make sense? Asgore’s memory persisting, Gaster’s inventions persisting … It all seems to point to one possibility: Gaster was never erased. He might be scattered, but his name and works are all penned clearly into the history of the Underground.

But then, what’s this talk about other worlds about? If he didn’t destroy his old dimension in the accident and create this one, without his presence, what’s the point? What is Goner Kid even talking about?

I think I know. I think that Gaster, sans and PAPYRUS are natives of another world who traveled here. Maybe not at the same time, but certainly in the same way. Consider what the Bunny Shopkeep says about the skeletons when you ask what there is to do in the town.

The implication here is that the skeleton brothers, PAPYRUS and sans, simply … appeared one day. Did they come from the city? From Waterfall? The RUINS? No. They just … appeared one day, and asserted themselves.

Remind you of anything?

How many times does sans talk about the place he wants to go back to? Who does he talk about never seeing again? He’s from another world, like Gaster. So is PAPYRUS. I’d argue that Gaster traveled to the current world from a different one, long before the accident, long before this Asgore and this Toriel even knew that he existed.



That Goner Kid’s quavering words reflect not how Gaster left this world …but how he came to it.