In the game Half-Life 2, there exists an ongoing mystery that has never been solved: The INTERLOPER Mystery.
SKY//BOX is an Alternate Reality Game by Anomidae
("A-Nom-Ih-Day"), focusing on a wide variety of Valve Software's Source Engine games.
At the very beginning of the Half-Life 2 level "We Don't Go to Ravenholm", one can find a mysterious piece of graffiti hidden down an alleyway. Specifically, it is an altered version of the "umbrella man" graffiti seen elsewhere throughout the game. Investigating the texture reveals a corrupted part of the image, hinting at the use of an "INTERLOPE" console command. This command works across multiple games that run on the Source Engine, and generates random gameplay demos when inputted. Upon further investigation, a mystery deep within the Source Engine emerges.
Somewhat uniquely for a video game-based ARG, the series is presented from the perspective of a user (Anomidae themself) investigating the mystery on their own and presenting their findings in a sequential series of videos. Many videos are linked to supplemental material that users are able to try and investigate for themselves, with a Discord server having been created to allow people to discuss the ARG.
The series starts with the video "INTERLOPER: Half-Life 2's Greatest Unsolved Mystery", and continues through various sequel episodes. For a list of every video in the series in both upload and chronological order, you can see our Timeline page.
Not to be confused with the trope Skybox, rendering a 3D game's sky as a cube that wraps around the world.
] get s.tropes.pull:27015
- 2-D Space: Discussed in "INTERLOPER 5". Upon trying to do 'expeditions' into the map void, Anomidae initially tries travelling in a straight, flat line from the initial map. After three failed attempts, they realise that they should probably try the Z-axis as well, which does end up leading to something.
- A.I. Is a Crapshoot: The INTERLOPER command appears to be linked to an experimental feature involving "DMNPCs", an attempt to create intelligent in-game NPCs via iterative learning. Eventually, these NPCs become so advanced that they can display human-like movement and behavior, which appears to have been seen as creepy even in-universe. These advanced NPCs appear to be the subject of the Type 5 demos, and are frequently accosted by the Umbrella Men for whatever purpose.
- Arbitrary Skepticism: Anomidae expresses disbelief in INTERLOPER 2 that alleged screenshots of a "DM Editor" are evidence of a real Source tool, and dismisses it as a hoax. The same video sees him triggering a Hint node that was seen in said screenshot while manipulating the aborted Type 5 demo, and the later discovery of Eida's videos suggests he's using a similar program for his work, but Anomi never comments on it.
- Arc Symbol: Checkerboard patterns and an XYZ axis appear quite frequently throughout the series.
- Artificial Stupidity: It is suggested that the Type 1 to 3 demos represent AI in the very early stages of learning how to play each game. That Type 4 demos are most common in Portal seems to back this up; Portal is a game where puzzles tend to lack randomness or moving elements, making it the type of game that an AI using iterative learning would do best at. The Portal 2 Type 4 demos seem to behave as if the AI has no clue how to interact with the new puzzle elements, seemingly reinforcing this further.
- Bad Liar/Blatant Lies: Anomidae claims to "not be a Source Engine expert" in INTERLOPER 4, despite previously being seen brandishing a Saxxy in INTERLOPER 3, an award given by Valve as part of an annual SFM contestnote (though this could be some Self-Deprecation on his part).
- Body Horror: What little we see of the Mona seen in the "I'm Done" video consists of a stiff, not textured upper body of a woman seemingly embedded in the ground constantly shaking its arms.
- What the Umbrella Men do to "captured" Type 5s seems to border on this, forcibly converting their models to "cheaple" citizens (as seen in "Misty") or stretching and twisting them in torturous ways (such as the "Hi Guy" in INTERLOPER 8)
- Breather Episode:
- INTERLOPER 7 effectively functions as this due to its framework as a dossier presentation on investigation finds, with no overtly creepy or scary moments being shown (bar the VRAD Error's sudden appearances and the uncertain note of the ending). INTERLOPER 5 has a similar vibe for the most part, particularly in its triumphant climax, but the ending's examination of Eida's "It's Inside my Computer here's proof" subverts this with a spooky observation and a literal jumpscare)
- A few of Eida Machinima Archive's videos are from before Eida got involved in his Interloper investigation, and simply feature classic Stylistic Suck antics in Garry's Mod with seemingly little overall story relevance beyond dropping a few hints about Eida's personal backstory. The best example is likely how "I'm Done. Goodbye.", a creepy short video that raises a mountain of questions regarding the Interloper mystery and Eida's activities, was uploaded alongside the self-explanatory "gary man eats tacos and DIES".
- Brick Joke: In "INTERLOPER 4", Anomidae sheepishly admits that they regularly play Half-Life 2: Deathmatch in their spare time. In "INTERLOPER 5", they are shown playing the game while waiting for a result from the first Z-axis expedition.
- Chekhov's Gun:
- Early in INTERLOPER 2, Anomidae brings up the suggestion that the demos could be linked to a defunct Source Engine tool called the "DM Editor", which they dismiss as a hoax. During the Type 5 demo at the end of the video, they discover the ability to place the exact same "Hint" prompt that the screenshot of the DM Editor showcased, revealing that it does have some relevance after all.
- Also in INTERLOPER 2, after his avatar is taken by the Umbrella Man, every subsequent boot into Portal loads his character into a small room with a red light illuminating the center that almost immediately crashes to desktop; in the video (as well as in the third video) he assumed that this is some dead end and that he couldn't get anything more out of the game. INTERLOPER 4 reveals that the RTX version of the game doesn't crash at all, and that his Portal game was actually turned into a local server through which other Source games can connect into, allowing him to use the INTERLOPER commands in Half-Life 2: Deathmatch again.
- Entry Point: The way to start interacting with the game is by finding a distorted "umbrella man" graffiti in an alleyway in the Half-Life 2 level "We Don't Go to Ravenholm". The corrupted part of the image reveals that an "INTERLOPER" console command is to be activated in multiple games that run on the Source Engine; resulting in new gameplay demos that hold clues.
- Foil: In INTERLOPER 3, Anomidae discovers a YouTube channel archiving the videos made by a person named Eida, who apparently did his own investigation on the INTERLOPER phenomenon. Eida directly contrasts Anomidae's technical, almost scientific approach to investigating by treating the "interloper ghosts" as if they were actual supernatural spirits, to the point of constructing his own Ouija Board-esque map for the purpose of communicating to the "ghost".
- Haunted Technology: Eida believes that this is the true origin of the INTERLOPER anomalies, though there is nothing to confirm this in the actual investigation thus far.
- He Was Right There All Along: The stinger to Episode 5 reveals that Umbrella Man was in Eida's final video – but the video quality was too low resolution to actually see him.
- I Fell for Hours: This is what Anomidae does in INTERLOPER 5 to explore the void, killing his character on 2fort and letting it fall out of bounds. For 6.5 hours.
- In Medias Res: Eida Machinima's channel archive is incomplete, meaning we only get to see small pieces of his INTERLOPER investigation at various stages of it.
- Kayfabe: Anomidae is both the creator of the ARG, and its in-universe main character as the person investigating the mystery. The very first video in the series presents itself as an investigation into a genuine long-standing mystery, only fully revealing itself to be an ARG with the "Made with Source Filmmaker" credit at the very end.
- Live Episode: INTERLOPER 4 was first broadcast ostensibly as a livestream, with an edited down version of it serving as the main episode. Out of Kayfabe it was still pre-recorded, with a Leaning on the Fourth Wall explanation of Anomidae not being able to easily see the chat as the justification for why they don't directly respond to specific comments. "INTERLOPER 8" is also presented as a livestream, this time with it being cut-off and what happens afterwards being elaborated on in the subsequent video.
- The Lost Lenore: It is implied that "Mona" is this to Eida in some form. She first appears in "Garrysmod Zombie Slayer" as the person Eida protects, calling him a sweetheart at the end of it. Eida's channel was originally named "Eidam0na Machinima", and his Interloper investigation is credited to "Eida-M0na", suggesting that the channel was supposed to be a collaborative effort between the two. The archive channel's description describes the content he made during his "breakdown" as consisting of many "Mona videos", and in his channel deletion video, he kills some kind of entity he dubs "the Mona". Given that he believes the INTERLOPER phenomenon to be paranormal in nature, the implication seems to be that he believes the haunting is linked to Mona the person in some way, and that his breakdown stems from him beginning to closely associate the entities to Mona herself.
- Maybe Magic, Maybe Mundane: The dynamic between Anomidae's science and Eida's paranormal investigation leans a bit into this. As the series follows Anomidae's perspective it heavily promotes the mundane theory for what is happening, but there still isn't anything to conclusively prove that there's no supernatural elements to it.
- Meaningful Background Event: Near the end of INTERLOPER 8, as Anomi examines his games following the Tuesday Manifest, he fails to notice in his Project Skybox mod that the head of the Lucy model from the last video is turning to follow his movements, up to and including her head turning backwards to face him.
- Mockumentary: Anomidae's "INTERLOPER: Half-Life 2's Greatest Unsolved Mystery" series is a set of investigations into the fictional mystery.
- Mythology Gag: The name "Interloper" is a subtle reference to the Half-Life level of the same name.
- Noodle Incident: The unspecified "breakdown" that Eida suffered prior to his INTERLOPER investigation, beyond suspicions that it has to do to with what "Mona" meant to him beforehand. The reason for his channel deletion is similarly vague, but recent evidence suggests the "mona videos" he made as a result of the investigation were part of an obsessive pattern that his friends and fanbase were negative towards, if not anything related to how those behind the anomaly might've responded to him.
- Right for the Wrong Reasons: Eida Machinima's investigation in many respects demonstrates a much stronger understanding of how the INTERLOPER anomalies work than Anomidae's own research. However, Eida approaches the mystery from a paranormal perspective rather than a technical one, making his assumptions about the kind of entity he is dealing with leads him to a wildly different conclusion.
- Selective Obliviousness: Episode 8 of Eida's ghost investigation reveals that his belief that a ragdoll is posessed by Mona is because of this. Already believing that he is dealing with something paranormal in nature, he takes it very seriously when it scrambles an alphabet to create a sequence of letters that can spell 'Mona' when viewed from a very specific angle. The idea that Eida was deliberately trying to find a pattern in a completely random set of results isn't something he considers. "Correcting the record 2013.1.2" more or less confirms this, as Eida seems to intentionally overlook and cut out the entity blatantly spelling 'Olive' infront of the camera before it scrambles together 'Mona'.
- Significant Anagram: The channel name "Eida-Mona" is an anagram of Anomidae. This especially highlights their contrasting nature when it comes to the INTERLOPER phenomenon (see the Foil entry above), as one need do little more than reverse the name of one channel to get the other's.
- Stylistic Suck: Eida Machinima's non-investigation videos are pastiches of 2000s-era Garry's Mod machinima, with poor audio and visual quality, base-level use of gameplay features, "Unregistered Hypercam 2" in the top corner and of course the use of "Blow Me Away" as a soundtrack choice.
- Weird Sun: A recurring trait of many Type 5 demos is that the sun has a strobe lighting effect that causes it to flash through multiple colours, with it also being visible through walls and scenery. This is a Source Filmmaker bug that is very easy to fix, so its presence in the demos appears to be very intentional.
