Searching For A World That Doesn't Exist is a Minecraft video created by Wifies.

AveryLargeMayo or 'Avery' is playing Minecraft when he comes across a strange mine in his single player world that he had not dug. The mine is well lit, has four doors on one side, each leading to a stripmine, and a chest with assorted items, one of which is a book, which he claims he did not write.

The book, written by an unknown author, contains some vague warnings of some nebulous, lurking being, and only one clear and repeated instruction:

'At the crossroads, don't turn left.'

With some digging, a viewer can find another video in which our protagonist decides to explore the mine. Instead of going into one of the strip mines, he decides to dig into the opposite wall and finds a cavern which starts showing some strange features the deeper one goes. What's more, with time, he realizes through subtle cues that he isn't alone.

Still he chooses to go further in, unaware of the terrible truths awaiting him.

Warning: This video has several twists that are best experienced first hand. The tropes list is very likely to spoil you. You Have Been Warned.

Searching For A World That Doesn't Exist provides examples of:

• Abandoned Mine: Avery finding one is, per the description above, the Inciting Incident of the story. Likely subverted for d3rlord3, though, as it seems he was the one to dig the initial mine that Avery found. And the caverns d3rlord3 found were likely not mines at all, but buried parts of the surface world.
• Admitting to Fear: Initially, d3rlord3 says that he isn't scared of whatever is following him, but after one of his traps confirms that he is still being pursued, he types the following to himself:
  I'm not scared but my gut says to keep moving
  Maybe I am scared
• Apocalypse Cult: The inhabitants of the underground village. The hermit's journal in the corner of the cavern mentions they've been trying to summon "The King" for some time, and then mocks them for acting surprised when the King did show up, with some disturbing implications.
• Be Careful What You Wish For: Implied for the inhabitants of the underground village. A journal in the hermit's home mentions they've been trying to summon "The King" for a while, and then acted surprised when "The King" shows up for real. Given the abandoned and dilapidated state of the village when d3rlord3 finds it and the hermit's mocking, it's hinted "The King", either the entity or another eldritch creature, "dealt" with them after being summoned.
• Beyond the Impossible:
  • The very nature of the world itself, which is noted by the protagonist in a png file to have been pre-installed when they downloaded Minecraft. For the record, whenever you start a new server or world in Minecraft, the world is randomly generated, ensuring no two worlds are the same. And in the case of Avery and d3rlord3's world, it very much isn't as its far too detailed to be randomly generated.
  • The ending features d3rlord3 returning to his starting point and filling out the journal that Avery would latter find. And the cipher? A warning for Avery specifically, who d3rlord3 should have no idea even exists, let alone that they'll stumble across his world years later. Then again, given the fact d3rlord3 encountered the King in Yellow, it’s possible he gained the knowledge of Avery’s eventual arrival and existence alongside all the other sanity-destroying knowledge he gained.
• Common Crossover: Fan crossovers with Oneshef's Collinlock16 universe are incredibly common, likely due to both engaging in subversions of traditional ARG tropes, though Searching For a World That Doesn't Exist plays itself more seriously than Collinlock16, which is a straight parody.
• Cosmic Horror Reveal: What starts as your standard Minecraft ARG gradually devolves in to none other than an adaptation of The King in Yellow.
• Covers Always Lie: The twisting structure featured in the thumbnail does not show up in the video.
• Cutting the Knot: After spending 17 minutes solving a mysterious cipher carved into a cave wall above a door, rather than try and solve the lever puzzle to open it, d3rlord3 instead has a much more pragmatic solution:
  d3rlord3: Unfortunately for you, I have a pickaxe.
• Darkness Equals Death: The final chamber d3rlord3 enters gradually grows darker until it becomes a void. And then you reach the gates.
• Decoy Protagonist: Avery. The player in the secret videos is not Avery, but another player with the username d3rlord3.
• Determinator: Mentally speaking. Even after gazing upon the King in Yellow TWICE, d3rlord3 not only tanked the double dose of infinite knowledge, but was able to hold himself together enough to flee and write the journal and coded message for Avery.
• Did You Just Scam Cthulhu?: d3rlord3 manages to outsmart whatever is following them by setting two traps to check if the entity followed them through the tunnel. The entity resets one trap to make it look like it wasn't there but not the other, and d3rlord3 acts like they don't know this before typing but not sending messages in chat to reveal that they do.
• Foreshadowing: There are a few hints that spoil the reveal that the character seen throughout the ARG isn't Avery, but d3rlord3, the book's author and the actual protagonist of the ARG.
  • At the start of the video, Avery's inventory is sparse and has very little. d3rlord3, meanwhile, has a lot more equipment on hand. Some eagle-eyed viewers will also note that when d3rlord3 opens the chest, the book isn't actually in the chest but is in his inventory, which he deposits in the chest for Avery to find at the end of the video.
  • Avery's Minecraft skin has him looking like a humanoid slime wearing a Hawaiian shirt, but later in the ARG, he's swapped it for a more regal-looking golden armor. d3rlord3 is the one wearing the gold armor, not Avery.
  • When explaining he didn't write the book he found in the mine, Avery mentions he's been playing Minecraft on a laptop he found in a storage locker, which already had it installed. A file in the google drive link contradicts his words, stating the world came pre-loaded when he installed the game. The second video in the google drive reveals the doc was written by the laptop's original owner and the ARG's actual protagonist, d3rlord3.
• Freeze-Frame Bonus:
  • When d3rlord3 sets a trap for whatever is after him, he puts a chest next to a hopper and fills the hopper with items, then lowers his render distance so he'll know whether the entity will have passed through since it will need to load in the chunk^note He also prepares a dirt and grass block as a secondary measure in case. When he goes back to check the trap, he finds the hopper still has the items... except if you compare the items' order to when d3rlord3 placed them, you'll find they're not how he placed them, meaning the entity filled the hopper back up to screw with him.
  • After breaking through the locked gates with his pickaxe, the chat bar lingers just long enough for the censor over the protagonist's name to disappear, which Wifles himself points out. It turns out the protagonist isn't Avery, but d3rlord3, the apparent original owner of the laptop Avery's now playing on.
  • When the protagonist towers up by the central fountain in the underground village to get a better look of the area, you can clearly see that the statue's head is missing. Oddly, no attention is given to this whatsoever by the protagonist or Wifies himself.
• Go Mad from the Revelation: Implied to be what happens to d3rlord3. After spending the whole video using his brains and knowledge of Minecraft to navigate the mystery, once he takes a look at whatever was behind the gate he books it in the opposite direction without stopping.
• Guile Hero: The protagonist is shown to be extremely intelligent, taking full advantage of game mechanics, solving a double-cipher by hand, and even managing at points to match wits with the entity.
• Hell Is That Noise: The entity's presence is heralded by a Scare Chord, shortly followed by loud whispers. The protagonist is clearly freaked out and books it the first time he hears it. When he hears it again while navigating the underwater tunnels, he digs into the ceiling and hides from the entity as it passes through.
• How We Got Here: Turns out everything in the files found in the Google Drive link was from d3rlord3, the original owner of the laptop, navigating the world himself long before Avery entered the picture, ending in d3rlord3 writing the journal that Avery finds in the beginning.
• Just Toying with Them: Whatever the entity is, it's intelligent. Enough so that it's able to initially trick d3rlord3 by replacing the blocks he placed to plug up the hole in the oasis and refilled the hopper. The fact it did this was clearly done to screw with him and lure him into a false sense of security, though it fails since d3rlord3 prepared a second trap in the form of a grass and dirt block.
• Kayfabe: A double whammy. As is the nature of Minecraft ARGs, we are expected to treat this as real while watching despite knowing it's fake but also Wifies himself treats this like any other ARG he's covered despite the fact that he himself created it, including pretending to be incapable of solving a cipher that, as the ARG's creator, he would logically know the answer to.
• Mind Screw: When the protagonist starts exploring the mine after opening a new hole on the right side, the tunnel he finds leads him to some unusual sights, including a large cavern consisting of nothing but stone. At the end of the ARG, d3rlord3 turns away from the golden gate after seeing what's on the other side and books it in the other direction, even mining his way through a wall... and finds the room with the chest he originally started in.
• Mundane Made Awesome: Under pretty much any other circumstances, using a pickaxe to bypass a trap in Minecraft would be unremarkable (and bad sportsmanship) but because most contemporary ARG protagonists of the time would never think of it, it becomes a badass moment and one of the ARG's signature scenes.
• My Skull Runneth Over: It is implied that due to the nature of the King in Yellow, by looking at him d3rlord3 was overwhelmed with infinite knowledge and this is what caused him to begin losing his grip on reality. This would also explain how he knew about Avery and was able to leave the hidden message for him, because the infinite knowledge also allowed him to see into the future.
• Never Trust a Title: The video itself in no way involves "a world that doesn't exist" beyond arguably the abandoned village. It seems to be nothing but a reference to another one of Wifies' videos, "Finding A Player Who Doesn't Exist".
• Nothing Is Scarier: The entity's form is never revealed, but is felt through multiple signs. Even when d3rlord3 sees it for himself, he chooses to put a large censor box over it. Though it's almost certainly for the best.
• OOC Is Serious Business: Normally, d3rlord makes sure to correct grammatical mistakes before sending a message in chat, but at the end, he is so scared that he writes his warning to Avery hastily.
• Screw This, I'm Outta Here!: After seeing whatever's behind the golden gates, d3rlord3 turns the other direction and gets the hell out of the caves pronto. It's never made clear what he saw, except whatever it was terrified him so much he leaves behind a journal to warn Avery.
• Self-Parody: Searching For A Christmas That Doesn't Exist is a video on Wifies' second channel, Twifies, that effectively plays out the same as the original, except everything is Christmas themed.
• Sequel Hook: The last lines of the video, as Wifies himself states:
  Wifies: ...But one thing is certain. Whatever was coming for [d3rlord3], is coming for Avery next. This isn't over.
• Survival Mantra: Doubles as an ominous warning, too. The book Avery finds repeatedly states "At the crossroads, don't turn left" over and over again.
• Stating the Simple Solution: Rather than try and solve a combination lock on a door with levers, the protagonist opts for a more pragmatic option and types in the chatbox, "Unfortunately for you, I have a pickaxe." He then proceeds to break through the door with his pickaxe.
• Uncertain Doom:
  • It's unclear what happens to d3rlord3, given how his laptop is discovered by Avery, possibly years later.
  • We're given no indication what happened to the underground village and why it was abandoned. Though considering they were trying to summon 'The King', it was likely nothing good.
• Underground City: The protagonist finds a small underground village while exploring the mine, desolate and largely devoid of clues except for the large statue in the middle. It's implied that this village might be Carcosa.
• The Un-Reveal: We never learn what the poem was that was carved into the cave wall and hidden under a double cipher. It is, however, solvable as someone in the comments did manage to crack the double-encryption. Turns out, it was hidden by a Vigenere Cipher and a Columnar Transposition of seven. According to them, the poem reads as follows:
  THESE EMPTY SILENCES HOLD MORE THAN THEY SEEM / THE WHISPERED SHADOWS DANCE UPON THE WALLS / AND IN THE UNSEEN MOVEMENTS OF THE AIR / THE POEM FINDS ITS BREATH 
  • The parody video released on Wifies' second channel Twifies reveals actual the poem to us, which reads as follows:
    Beneath the sky of melting gold / Ancient echos of a shepard's mold / An old decay if left one goes / Is unseen truth all but faux
• Unseen Evil: We never get to see what was following d3rlord3, nor do we see The King In Yellow. Although in the case of the latter, that's probably for the better.
• Wham Line: The decoded message from the journal revealed at the very end:
  Rvn Avery, it's here.
• Whole-Plot Reference: What seems to originally be just a spooky Minecraft ARG eventually turns out to be a stealth adaptation of The King in Yellow, with the video's antagonist being the titular king himself.
• You Have Outlived Your Usefulness: Possibly. The hermit's journal in the underground village mentions the inhabitants were trying to summon 'The King' and mocks them for being so surprised when it does show up. Given how the village is abandoned and damaged, it's heavily implied 'The King' disposed of them after being summoned. That, or its mere presence drove them all off the deep end.