 Portal 1 is somewhat of a black sheep. It's one of Valve's shortest titles, a puzzle game standing amongst their catalog of violent shooters. But thanks to its captivating design and an extremely characteristic marketing campaign, it's managed to stick out and become a staple of the company. Nowadays, Portal is seen to some degree as Valve's child-friendly IP, in part due to the Pixar-like sheen observed in the game's sequel. But there's no denying that the original game carried somewhat of an oppressive, dark, and mystic allure by comparison. And the same is true in regards to its cut content. While Valve's other games have sprouted huge communities around their scrap material, equipped with inside jokes like Half-Life 2's free TVs gag, or even Portal 2's Wheatley Crab, Portal 1 had nearly its entire developer repository leaked online nearly seven years ago, with comparatively very little fanfare. As far as most people are concerned, after the game made a switch from a Nova Prospect-style facility to the defined Aperture Laboratories location, things were relatively straightforward from then until launch. And they could be forgiven for thinking that. But with revitalized interest in the franchise due to Aperture Desk Job and the Companion Cube collection, a more opportune time couldn't have arrived for a new discovery about Portal 1's development to be made. And the craziest thing? The evidence has been sitting in front of the Portal community's eyes for ages, but to my knowledge, barely anyone had put 2 and 2 together until now. Introducing Ossie Floul. Ossie's a good friend of mine. I have him on my streams pretty regularly. He's a huge Portal nerd, possibly the biggest in the world, and I owe today's video in its entirety to him. See, Ossie runs a channel where he covers Portal topics. He's worked on a multitude of Portal mods including the upcoming Portal 2 Desolation project, and he is generally speaking a walking encyclopedia when it comes to this franchise. So when he offhandedly mentioned a cut ending involving the alien dimension Zen from the end of Half-Life 1, my ears perked up. Because not only did I find it incredibly interesting, I also knew it wasn't something he'd just made up. Within the files of Portal 1 there's a Skybox texture called Sky Escape 01. This Skybox appears to be an iteration of C4A1, the opening level to the Zen chapter in section of the original Half-Life. A lot of people I think dismissed this as nothing but an odd leftover from Half-Life's source, since that game had its own share of weird development assets, like the developer demo that mashes up random levels of the game in a surreal experience. However, after looking into it further, that doesn't seem to be the case at all. To explain the nitty-gritty bits, I'm gonna hand it over to Aussie since I'm not super familiar with mapping and hammer. Hey everyone, the name is Aussie Flowerhole. As Richter mentioned back there, the Skybox texture is called sky underscore escape underscore 01 underscore, and it exists in the final game's files and is incredibly low resolution. This is because it appears to be a cube map reflection turned into a Skybox, almost certainly a placeholder. The name of the Skybox indicates to us that this would have been used in the map Escape 01, which is the third map of the escape sequence of Portal 1. But Portal 1 is a feature in the Skybox textures in the section of the game, so what gives? Well, our answer lies in an Uncle Pie map file. Most of the time, source games don't come repackage your death files like Uncle Pie levels, but in the case of Portal 1, they've been floating around online for nearly half a decade by now thanks to a legal leak from Valve's internal repository. If we open up Escape 01's original VMF in the hammer editor and check the properties of the map, we can see that the Skybox parameter is indeed set to display sky escape 01, but as we established a moment ago, the map itself has no visible sky textures. So what gives? Well, if we turn our attention to the VisGrips tab, we notice a few unchecked boxes. Oftentimes, in most Valve maps, re-enampling hidden VisGrips will reveal unused or cut segments of the map, and this is no exception. Taking the Steaming Refuse group reveals an early iteration of GLaDOS chase boss fight. See, Portal 1 originally would have ended with Escape 01 as a second escape level, but likely for performance reasons, Valve split the map down into Escape 01 and Escape 02, with the GLaDOS boss fight appearing in the ladder. Attached to this newly revealed boss fight area is a room feature in a generic rock texture of Half-Life 2 Episode 2, alongside some pale white lighting. Now, we just need to go down the whole way, and hey, look at that. This is where our mystery Zen Skybox texture was used. Given how long the Portal files have been floating around, the fact that something like this seems to have completely flooded under the computer's radar is incredibly surprising. I'm sure a lot of fans of both Half-Life and Portal would have been obsessed with the concept of Portal involving Zen in some capacity. But how exactly did its iteration of Portal use Zen? Back to you, Richter. Well, as established, this ending involving Zen was to follow an early version of the GLaDOS boss fight that would have appeared in the second escape level, which looked a lot different to the final version we got. GLaDOS is represented as an arranged cube of floating roller mines from Half-Life 2, and the player would have had to chase her around the map and use turrets to damage her. Once she's defeated, these brushes would have broken open, and the player would then portal through the newly opened hole on the wall. Walking out of this blocky, cave-like structure, they'd exit on a ledge and look out into the Zen atmosphere. After this, the game would end with a fade to black. This, of course, is extremely confusing, and leaves us with more questions than we have answers. The most prominent obviously being why the hell is Zen being projected outside of Aperture Science? Well, of the possibilities I can see, there's A, that the Aperture facility was meant to be based in Zen. It's certainly hard to imagine a version of the Portal universe revolving around that concept, but I'd like to draw your attention to a line from the pre-release Portal 1 ARG. On the ApertureScience.com website, an Aperture employee remarks that he doesn't think going home is part of his job description This ARG was started around the same time that the Zen ending was still in place during development, so it's definitely interesting to imagine what implications that line might have carried. B, that the Skybox texture is a placeholder meant to imply that the Aperture facility was its own dimension. This one is somewhat intriguing as well given the endlessly expansive portrayal of Aperture we see in Portal 2, but there's not much else to support this idea. C, that the hole in the wall is not a physical breaking point, but rather a rift in reality caused by GLaDOS' destruction that Shell travels to Zen through. This is pure lore speculation, but it's possible that Aperture's Portal model may have mirrored Black Mesa's in how it uses Zen as a slingshot. That would definitely be a candidate explanation for why destruction to GLaDOS and the greater facility could bring about a rift to Zen. Regardless of which of these may or may not have been the case, you've got to admit the fact that one of the developers went out of their way to generate their own Zen Skybox seemingly just for use in this ending is incredibly intriguing. And while it may seem strange looking back, the idea of Zen being linked to the Portal franchise is not actually that weird when you think about it. After all, Zen is considered the border world that connects dimensions, and was accidentally discovered by Black Mesa during their attempts at Portal and teleportation technology. It's not that hard to imagine Aperture accidentally uncovering Zen as well. Prior to Portal 1's release, many developers hyped up the game's connection to the Half-Life universe, and it's very possible that this cut Zen ending might have been one of the driving factors behind that. Now I've got a confession to make. Technically, at this point in development, Chell as a character wasn't really developed, so I'm sorry for the clickbait. But it's still interesting to view it from a retail-adjacent lens. Would the protagonist simply have been stranded in Zen, or would they have found a way back to Earth? Interestingly, this ending does seem to imply that Zenland forms their Portal-accessible surfaces, and we've seen characters from Half-Life and its expansions return to Earth from Zen with little fanfare, so I wouldn't rule out the latter. Doug Lombardi was even once quoted in a pre-release interview saying that the Portal protagonist would appear in a later Half-Life game. Maybe, just maybe, the Zen ending was part of that. Anyway, that's all I've got for this video. If you've got any theories or information regarding this ending, leave a comment below. I'd love to read it. But before you go, check out Ossie's rendition of how the ending could have looked with some polishing up, utilizing Half-Life's sources assets. Thanks for watching. Have a good day.