Per 
;)
So, it's a murderous, sentient, corporeal entity stronger than a human with multiple memetic properties and a dimension-switching ability. It normally splits its time between some room on Earth (prior to complete containment, its last location was a testing room of Site-XX — before that, who knows) & some void in which it is the only entity that exists (basically non-existence). It is only visible for the first instant that an individual sees it - it then becomes invisible and can only be detected through hearing (i.e. it cannot be recorded on devices) or when it physically interacts with its prey. This is normally done by quickly lifting its victim, holding them in front of its invisible face, and breaking their neck — ONLY when any recording devices or witnesses are present. Otherwise, it just maliciously but non-fatally trolls the sole victim. NOTE: this setup is to make it appear as if it'll just be another spooky OP monster at first blush, but the further one reads, it becomes clear that this stuff isn't even what makes it scary, and also does it no good to prevent its containment, so it's ultimately a macguffin (and makes up a very small part of the overall work, these are just details provided here to make it easier to conceive - in action, they'll appear somewhere in the middle of the entry).
Its driving force is that it is determined to enter the collective consciousness of humanity (known to it as The Biggest Place) and subsist off it eternally, basically enslaving humanity as mindless drones to be picked off at the SCP's whim/hunger.
Containment was achieved when it was trapped in a recursive location-based concept by Foundation staff. This is obtusely explained (at first) as a place being perpetually created and destroyed - more specifically, the reader is told that the SCP is secured in Site-5, which establishes the concept of a Site-5 in their mind, but then the reader is obligatorily reminded that Site-5 does not exist, obliterating the concept. Through these various explicit reminders (meaning, this SCP wiki entry's containment procedures, plus all the Site-5 footnotes scattered throughout the wiki), a conceptualization of Site-5 is generated, in which the embryonic/larval/first form of the SCP begins to slowly develop. When a person who has conceived Site-5 is reminded that said location does not exist, the conceptualization is destroyed, along with all progress made by the SCP in its development. When deconceptualized, the SCP returns to non-existence and restarts its growth cycle from the beginning. The implication is that enough staff access/read the database that it is continually reset, and THAT is the true containment procedure, but for reasons explained elsewhere in the work, the less wholly-accurate information shared about the SCP, the safer (because isn't that always how memetics go).
If the SCP were to fully develop, either in reality or non-existence, it would eventually attain the ability to breach reality/non-existence at will (albeit with a bit of effort), upon reaching maturation. Its goal is to have a high enough percentage of humanity believe that the SCP exists within our collective consciousness that it allows the SCP to open NOT a portal between reality and nonexistence, but RATHER a (unknown word.. like a door, but only with a % chance to go where the entrant intends to go, while the other % means the location leads to non-existence in a manner similar to deconceptualization, meaning all developmental progress that had been made by the SCP will again be reset). It is not made clear exactly what the SCP will do when it gets into humanity's collective consciousness, but based on its food source (basically the spirit of a person), but since this awful thing views The Biggest Place as some sort of paradise for it, we know It Ain't Good.
The SCP's big-deal form of travel is to open portals between existence/non-existence (a bit similar to the melty homeless SCP) because it is all but forced to do so - in reality, it can only exist in either the non-existence void or where it is being conceptualized, meaning A) the place that it is imagined to exist, or B) the place it first breaches reality if it eventually develops the ability to do so while in non-existence. Besides this form of travel, it seems to teleport/relocate at will anywhere within the room it's entered. This allows it to ensure no one leaves the room alive unless it wants them to, although it much prefers to prey on individuals in an agitated state (more on this later).
Despite non-existence being infinite, the SCP does not view it as such, and rather abhors it in a manner similar to claustrophobia (thinks it's oppressive and stifling, etc). Instead, it attempts to breach locations that are as large as possible, but has not yet breached an outdoor or open-ventilated location for reasons unknown (spoilers: it can't). Leading hypothesis is that the SCP can sense locations from non-existence; it will find a spot it has sensed to be acceptably large and wait there until the reality-breaching ability is attained, then shift to reality and camp in that location. It is indestructible with any physical means, and is extremely hard to track due to the initial instant of seeing the SCP being the only time a subject can see it before it becomes permanently invisible to the subject (basically, it blinks out of existence almost faster than the human eye can first recognize its presence). It affects humans through sound, as it almost constantly makes a heavy, long breathing sound combing with a muffled thumping sound. Doing this agitates anyone in the room whether they can actually hear it or not - at one point it's suspected as something to do with neurochemicals, which is how a specific neuroscientist gets involved later down the line. Anyway, whoever gets the most agitated is almost always picked as the prey, but it's unknown what triggers the attack/tips the scale as making a person able/chosen to be preyed upon (spoilers: it's because freaking people out spreads the panic, and the story, further - more people aware of this thing, the more it's in the SCP's favor).
Whenever it preys upon a human, as the human is clutched in its (who knows what), it can sense a location inside that human, a location greater than any the SCP has ever sensed before in its infinite existences, and it can even tell that this location is full of what it feeds on, full of what it desires, moreso than any location it has ever found, than it has ever dreamed of finding during its (what feels like) millennia of lying in wait while in non-existence. It interprets this place as being the antithesis of the realm it is continually returned to against its will — ever-expanding and full of life. In short, the SCP recognizes a glimpse of heaven in each human it feeds upon when it briefly sense the collective consciousness, and it wants in bad.
This drive to reach The Biggest Place fuels the SCP, and it bides its time knowing that its plan "has" to succeed at some point. The overall plan is this: make humans believe that that the SCP exists "outside," i.e. the surface of the Earth. Once it can exist on the open surface of the earth and use its teleportation abilities to travel across the planet basically without a trace, it will be able to infect humanity to the point of entering the collective consciousness. BUT, this plan can't just be handed to the reader on a silver platter, it's some unknowable being's thoughts! Which leads to…
Toppest Secretest Information (stuff behind Clearance walls)
An interdepartmental Foundation research team formed a brain tank (metaphorical, not literal) whose eventual goal was to determine the most efficient approach to entering our collective consciousness. This goal was set by the O5 - no holds barred, all stops pulled - upon the realization pointed out by somesuch doctor in this team that, based on the SCP's apparent intellect (determined through messages mentioned further on), if the SCP truly does have nigh-infinite time while developing in non-existence, it has assuredly worked out a plan to do accomplish its goal, if not the most effective plan possible based on the time factor alone.
The general life cycle and abilities of the SCP were already known for a bit of time due to testing and the soon-to-be-described messages, but it wasn't until one specific message that allowed the Foundation to determine the fuel source of the SCP that the think tank was brought together (as they assumed The Biggest Place was all but imagined by the SCP until this message). They were stymied for a few months because they didn't fully grasp the SCP's understanding/views of the human consciousness, but upon realization of what The Biggest Place was, they were able to get to work, and eventually crack the code that shows how terrifyingly easy it would be for the SCP to enter our consciousness were it able to be heard by the overwhelming majority of humanity (thereby establishing its presence), and that containment at that point would basically only be capable by destroying Earth. [This will reinforce the importance of all three aspects of SCP - absolute secure containment as the only way to guarantee protection of humanity], and if it gets into our collective consciousness, we can't even do that.
The path that the think tank cooks up? The whole purpose for the toppestest secretest info? Just the simple notion, "It's all in your head." If the SCP can attach itself to the "it" in that phrase (which it ostensibly could by stalking people), then often enough, just the very conceptualizing of "in your head," even metaphorically, opens the slimmest (unknown chance-door). If enough people do this, even passively, the SCP will grow confident enough to attempt the breach. The scariest part is that it's it's not a set number of humans that make it possible - this is based on chance. And the reader has read the idea, and conceived of the attachment (because of course they read all the stuff).
If the SCP were brash enough - or grew desperate enough - even that one conception, currently occurring by the reader, that one chance, could be taken, and if it got lucky, we'd be ruined forever. (Note: the think tank got the full A-amnestic treatment after determining and recording this goal to minimize its impact on the odds, and the "author" of the SCP page got the same after logging this behind the clearance thingy (the author being the neuroscientist mentioned below.)
And think about how quickly people are to turn to such words that are intended to be consolatory, dismissive of their fear. And this article turns that consolation into something to be feared.
EXCEPT! The Site-5 trap! This was devised by some kewl-ass teamwork via the head of the a neuroscience department and an anti-memetic researcher. The researcher was capable of entering the location that the SCP had entered from non-existence, and the neuroscientist gave him what was basically a program in chemical form that the researcher injected himself with, which programmed his mind to recognize the SCP as the SCP, but also recognize its location as being Site-5. The final step of the program is the realization that there is no Site-5, which the researcher of course says aloud when he realizes it, and the SCP instantly dematerializes. (Of course, this means it is developing again somewhere in non-existence, latched onto some new huge place, just waiting… maybe this one will have a skylight that opens, or maybe a cave that's susceptible to collapsing soon, maybe even in the next century, anything sooner than this eternal, crushing, silent nothing.)
Now that the SCP is logged under its appropriate #, with all the stuff we want people to see sitting nice and neat out front (see below for Level-1 Clearance entry) - the neuroscientist has been rereading the article over and over to simply help wish it to be true, the only thing he can do after his contribution - the SCP has been contained. Wow! A success story for a memetic XK-Class SCP. Unless, of course, anyone were to ever learn this stuff without getting amnesthetized and think to themselves, "It's all in your head…" like……. THE READER, MAYBE??? ULTIMATE SPOOP!!!
The anti-memetics researcher first identified the SCP by happenstance - while it had been hypothesized to exist (with traces of evidence or hearsay as all to go by until the sighting), it was not identified until the researcher was in a special testing chamber built for SCP-XXXX - it'll be unrelated to all this stuff, but it's necessary here for the sheer size of its testing room that drew the SCP to it in the first place. Starting on XX/XX/20XX, whoever went into this room containing whatever Euclid-class SCP-XXXX would for some reason die, one at a time, but for some reason, containment never got breached (meaning, people all over didn't get killed when the door got left open), and whoever was in the observation room during these was also perfectly fine (hence why researchers kept going there after the deaths - they just can't help their curious-ass selves).
A few weeks in, somesuch researcher was in the middle of taking his scheduled mnestics (which he has to take due to his previous work with SCP-XXXX (link to the anti-memetics dept here) when he made first visual contact with the SCP. Because of as-of-yet undetermined abilities/meds compounding the mental state of the researcher, he retained visual identification AND the mental state of the SCP (more on this later) - however, they did not grasp the scope of the SCP's threat until they had begun testing already, and because the researcher was run through the wringer to determine if he had become anomalized or twigged in some way (aka "getting -1'd"), he did not witness any of the testing (also described later), which would have allowed them to identify the threat and begin effective containment procedures much more quickly. However, the SCP is instead fed some Disposable-Classes which just made it more powerful than it originally was (because of course they have to fuck up somewhere, the Foundation can't just do all this shit right, right away).
When the researcher is finally able to get back on the other side of the observation glass, he meets the neuroscientist who had recently been put on the team. The last person who had his position was his supervisor, an original member of the SCP-XXXX Think Tank who got killed by the SCP when the conceptualization of "the room" unintentionally grew to include the observation side of the glass. This occurred when more than one D-class in testing thought of the observation room as part of the room as a whole - whether this was intentional or not is up in the air - but it's no longer an issue due to the revised procedures in D-class conditioning for testing. Anyway, recently-promoted neuroscientist totally buys all the stuff that the researcher says (of course the last guy didn't buy it when he was observing the post-discovery interviews with the researcher) because his details fill in the gaps of what the neuroscientist had been observing in testing, and more importantly, helps explain at least one or two the obtuse message(s) made by the SCP.
These messages, when paired with the researcher's info, include revelations that the SCP hates its alternate reality, that it hates its anti-memetic properties at times while at other times boasting about/beatifying these properties, and that The Biggest Place was "discovered" while the SCP gripped a person and stared into his eyes for the first time, forever ago.
So how are they getting the messages? Upon first sight of the SCP, right as it blinks out of view, its state of mind is planted in the head of who sees it. Based on the information provided, it has been determined to be an unintentional effect, and potentially even unknown to the SCP itself. Now to the collection of the messages: eventually the testing procedure is developed so that any D-class sent in have been doped up so that they remain calm but relatively lucid upon entering the room. They are also inaccurately briefed on the mission so that they most efficiently serve their purpose before getting iced. They are to ignore any physical descriptions of the SCP or what they are experiencing, and are instead to begin loudly and quickly saying what's on their mind. When this testing began, they got a lot about its feeding method, but eventually developed the briefing and D-class selection so they could receive reports on whatever seemed to be most beneficial to researchers. This will include an unrelated field agent who elected to perform the duty after being exposed to SCP-XXXX (actually find an old SCP for this) which is effectively a death sentence. Footnote: the agent's widower and family received double benefits after the test was performed, and a sweet lil thank you for ur service to the agent goes there too, signed by the later new-research-head.
These messages are used by the Think Tank to develop some kind of failure-of-a-solution that they test using themselves instead of D-Class, due to the fact that it requires full knowledge of the SCP to kick in. These dinguses think it works at first - a Think Tank member enters the testing room and upon identification of the SCP he administers the "solution" to himself, then goes through a chain reaction thought process that renders the SCP wholly unrecognizable to him. However, should multiple individuals take the "solution", the moment that more than one person observes the room containing the SCP, the "solution" is immediately rendered ineffective, because they do not share the same conceptualization of what the SCP is - just what they ought to think about it. All they did was invent the brainfuck version of a SCP-XXXX mute button. Of course, the SCP does not manifest immediately, but waits for maximum spoop! IDK how yet, but all the doofuses but the neuroscientist and the researcher get iced. The neuroscientist cooks up a super version of the serum last-minute, and the one person who has full conceptualization of the SCP - the researcher - marches into the testing chamber to administer the proper solution while the SCP is holding him by what feels like some kind of scaly and muscley… thing.
Lvl0 - primary page
Item #: SCP-$$$$
Object Class: Safe
Special Containment Procedures: SCP-$$$$ is located in Site-5. (requisite footnote) The SCP has been contained due to the preceding information. No further action is necessary.
addendum: "The information on record is accurate; while the diligence of those who have attempted to report potential discrepancies is appreciated, it is unnecessary. The O5 council unanimously affirms no further action is necessary."
O5-blotblot
(lots of blank space)
(expander with some threatening business about security and necessity of reading dependent on assigned group)
Lv1a 1b
This is split into halves: one is a more accurate description of the SCP's physical(???) attributes and hunting activities (basically, for tactical type stuff), the other is a more accurate description of the current containment situation and the SCP's messages in redacted form(for eggheads to read and further research if necessary) with reference to a specific document they can request for research purposes that is less redacted if necessary (not actually linked, but mentioned in the next level). The idea behind the bifurcated information is that the Foundation assumes it's a bigger liability if the mid-level people are aware of both halves simultaneously, infohazard style. The sections are pretty short, though.
(expander that says this section is for anti-memetic researcher staff on emergency basis)
Big Daddy Top Tier
Perhaps opens with an infohazard? Do people even still do that anymore
Describes the findings of the SCP-XXXX Think Tank, the implications of such, and that the issue was resolved, with the result being the Level 0 entry. A word there will be a link to the narrative tale, and another will link to the O5 Eyes Only memorandum that contains all the spoopiest stuff.
