Black Mesa Dragon Rookery is located on a 'near Earth' which has common features to a number of worlds. The presence of two facilities, Black Mesa Research and Aperture Science, are on many of those worlds. The history of this specific Earth includes a Resonance Cascade which breeched dimensional barriers, leading to a number of alien incursions via "portal storms" which sweep across both Earth's countryside as well as another world at the same time. To keep the population safer, 'Cities' had been made, some on existing locations and others set between larger but ruined centers. The countryside was emptied, and the Cities contained threats more easily than individuals could. Some years after the Cascade event, another full alien invasion force arrived, the Universal Union, also known as the Combine, or in Vortigese: Ulathoi. Because the Cities had many of the remaining population, they were hit with massive structures, Citadels, that facilitated the 'Seven Hour War' - when most of Earth's military was destroyed, and where the surrender of the world was negotiated.

This world's Earth contains numerous non-native intelligent species, in addition to the existing Human population. Vortigaunts, escapees from Xen, aid the Humans against the presence of their old enemy Ulathoi. Ulathoi is composed of hundreds of different species that have undergone surgical and cybernetic alteration and all obey their 'Overwatch', under the direction of off-world leadership. Ulathoi treats itself as though it is one organism, with specific creatures filling cellular roles. Their eventual goal would be, like any other world they've captured and used, to satisfy their own Overworld's replacement part needs, gain weaponry or technology that can be used with their own forces, and siphon whatever is left as fuel. The presence of intelligent life only means the potential for new equipment, rather than any form of cultural exchange.

It is in this bleak, ruined world, that the series of color-coded genetically engineered clone girls and boys were made, at Aperture Science's Enrichment Center, located in Munising Michigan. Though they were sent out from that location to other dimensions for schooling, their return with dragons has complicated things for the facility's only other inhabitant, GLaDOS. Since she is unable to leave that location, and dragons are hardly fit to live in the strange underground locale (they could, if not for all the equipment in the way), another has filled the need. When the Aperture facility is rebuilt and the Testing Spheres made ready for inhabitation rather than dangerous science, a great many people may start living there safely, which happens around Rookery Year 12.

But those facilities aren't just located on only the Rookery... The multiverse at large contains myriad versions of Earth - and all other worlds, for that matter. What happens on one, may not have gone the same way on all of them. For the sake of sanity, the main contributors of character types in the Rookery are those from Black Mesa, Aperture, Armacham, and Rapture. Others come along, with variations below.

The diverging paths of the different Earths usually hinges on whether Ulathoi is destroyed and how it is done. On the Rookery earth, Gordon Freeman didn't make it through Black Mesa, and Adrian Shephard was not released from stasis by 'their' Vahh yet or was taken back into his control and not released by the Vortigaunts (as seen in Episode 1's intro: episode 1 therefore did not happen in the Rookery, it would have been Adrian instead anyway) - thus the Combine's reign has continued. On Repurposed Earth, Freeman did survive and was released some 8 years before he would be on others, and that combined with the presence of exceptionally strong Vortal humans did the Combine in.

Notably, the undersea city called Rapture exists on many of these same worlds, but is more often than not in a state of absolute ruin before 1970. Some of the research done there aids Lane on numerous Earths, as he was rather enamored of one of the locals by the name of Rhea Mercer. If she existed, it's highly likely that Lane had fallen in love with her, and probably tucked her away in Vortal safe keeping. Her pregnancy - or lack of - is often a key feature of whether that world's Lane turns against his own kind, they turn against him, or whether he is actually working against Humanity in the first place. (I concentrate mostly on those who are aiding, protecting, or at least neutral.) After all, breeding with the natives is expressly forbidden - not that he's ever followed all the rules of the Convocation... Note that while Rapture in its 'pure' form (Bioshock) exists in its own set of overlapping dimensions, ones which we encounter with the Rookery will have only limited connections to those others. Lane doesn't like Rapture as a physical spot because it's... under the goddamn ocean, but he dislikes Columbia even more, and for much more personal reasons. It might be floating in the sky - and he's fond of ravens and open air - but it's a shitshow of racism and intolerance, and he is just not about to visit it without wanting to blast it out of the sky himself. The presence of a bizarre 'sea with lighthouses' - a vision of all the potential dimensions available to those who are from the Rapture-centric Earth, does cross over, though poorly, to Xen. Of interest is that those various Rapturearths that have no hint of Black Mesa, Aperture, Armacham, or whatever else, have also been known to have Portal Storms - perhaps 'tears' as some local Columbia inhabitants know them. This doesn't happen often, but it has the same effect as any other world's overlap: people show up to the Rookery through them.

Another crucial difference between the Rookery and Repurposed Earth is the presence of the Armacham company. A cut-throat business with its interests mainly military equipment and clone soldiers, communication satelite technology, and war profiteering. Run by the entirely disagreeable Genevieve Aristide, and having a group of political backers to supply massive funding, greed tends to blind most of the upper-echelon Armacham investors to the dangers of creating super-powerful psychic commanders and messing with children who could, in their 'fathers' words, "become Gods among men". Armacham, however, doesn't exist on the Rookery, and did not provide Lane with any clones, support, or errant hyper-Vortal children to defeat the Combine, as they did on Repurposed Earth. The combination of Armacham, Rapture, Aperture, and Black Mesa, is usually what 'fixes' things and bodes best for the outcome against the Combine. Without one or more of those... Things tend to go south quickly.

Some other key players from any given world include Chell and Paxton Fettel. On the Rookery Chell was a daughter brought in for testing to the Enrichment Center, who never left, and who was cloned numerous times by GLaDOS in order to facilitate testing on equipment. She may yet exist somewhere in the storage facility there, unaware of her own role in the entire process. On Repurposed Earth, she is one of many 'Expendable Labor Lifeforms' created by Armacham out of the genetic material comon to both worlds. She and her sisters with a variety of '-ell' designated names (like Zoell, Kyell) are part of the future of Repurposed Earth. When you see GLADOS, with 'A' and not 'a', that is Repurposed Earth (standing for Genetic Latency Aggression Deterrance/Observation System, a facility designed to keep Alma Wade in check); with GLaDOS still meaning Genetic Lifeform and Disk Operating System on the Rookery. Paxton Fettel does not exist without Armacham, thus Rookey Earth did not have him - or his mother Alma - to focus onto the Combine and destroy it. Paxton on most dimesions is also known as Xkah Shu'Vahh, 'the Inheritor of the Mystery', in some way directly connected to Keenan Lane. Whether it's because he's cloned and that clone sires offspring, or Armacham has taken liberties with what DNA was given to them in the first place, Paxton tends to be remarkably talented and strong enough to be considered Convocation himself. On worlds where Armacham exists but Black Mesa does not (such as 'canon' FEAR), Paxton is unrelated, but likely just as powerful.

Complicating all of this is also the rare but important appearance of Dimension X; a dimension where the Combine didn't even exist, but the Convocation, Lane's people, were much worse, and their interference might be felt in more ways than just having Cave possessed or Lane having an extradimensional daughter recreated in the flesh... It may very well be the GLaDOS from that dimension that overtook the Rookery's to do much of her less-deadly work. Little is known of the place, but it seems that a lot of roles are switched around there. Enemies aren't always allies, but sometimes they can turn the tide - just not on their own dimension. It's not clear whether Nihilanth exists in that dimension, but it is certain that numerous Vortigaunt and adjacent species do, though they are still all considered allies, and not reversed into oppressors themselves.*

*It is known that almost all Vortigaunt lines can detect one another - even across dimensional barriers and alternate worlds. This doesn't necessarily mean they can communicate with or contact those others, but they all eventually become 'part of the All In One, and that 'all' actually is, all of them, stemming from a hive mind that spans any Vort-bearing dimension. If anyone figures out how to tap into the millions of Vorts living across disparate dimensions, destroying Ulathoi will be easy...

A considerably weirder but more or less 'friendly' dimension, Aperturth, is known to have had a human born Keenan Lane, no sign of Black Mesa as a prominent player (it does exist, it's a bit of a joke there), but Aperture Science Innovators dominating the extremely weird disasters that befall that planet. Time is a bit off-set from there, as they seem to still be stuck in the 1980s, and the hippies and carnies that Local Lane brings to the Rookery from there arrive around 8 years after everyone else, and a couple years later a set of escaped convicts, experiments, and a troupe of guards and swat officers follow. Whatever happened on that world may have repercussions later, as they're known to involve time and dimension travel, but the place needs to heal up a little before any further exploration can be done on it. It's known that their version of the Resonance Cascade involved a large number of Aperture facilities 'going off' at once, and setting off latent Vortal or Psychic powers in... well, the entire population of the planet. Given that Aperture was experimenting with cloning, DNA, mind powers, and the like - this might have serious repurcussions, or it might just wind up being one of those weird-ass superhero planets. No one knows yet. A decent number of people from that dimension have been brought here already though. It is clear that Aperturth's background mutation rate is quite high, it's right on the edge of being a 'superhero' world already - very similar to Paragon's 'Prime' and 'Praetorian' Earths.

Speaking of those: Yes, Lane is a superhero at times. Or a supervillain. Just depends on his mood. The permissiveness of the Paragon-centric worlds is quite attractive to him, the ability to just let loose and do what he wills, it's like a playground for him and many versions of him. Some are active cloned bodies like those residing and teaching in Carramba High, and doing good, others spend vacations there causing havoc in the Rogue Isles. It is one of the few worlds where Black Mesa (Blackwell), Armacham (Crey), Aperture (Portal Corp), Rapture (Aeon), and most other locations don't exist at all - and yet, all of their roles are filled with different companies. Also it's one of the very few worlds where you'll commonly see people at least as powerful as he is, if not more so, wandering around looking for purse snatchers to put in jail. Paragon Earth has its own 'Xen' dimension, the Shadow Shard, which absolutely does cross over into Xen very fluidly.

Worlds without any of the above companies still manage to successfully cross over or be visited by the genrehopping sorts, particularly Vault Earth, which has grown in importance after the arrival of those weird-ass hippies to the Rookery. It is a world where Vault-Tec dominates the post-apocalyptic landscape even long after the board room meetings and construction of Vaults ended. But also the dimension has had aliens and monsters, some of them really, really frightening, exist on or near Earth since humanity began. Cthulhu may very well rest in an endless slumber somewhere in the depths of that Earth's heavily polluted seas, and though they are intelligent aliens, the Zetan life forms are thankfully nowhere near as powerful enemies as the Combine - or the Vault Dwellers. Psychic powers actually exist in this universe already. Notably this version of that world is non-canon to include the FEV (Forced Evolutionary Virus) being apt to allow the resulting Super-Mutant to be slightly more fertile than 'not', and can be passed to offspring of half-Super-Mutant pairings, as well as the incidence of Ghoul-creatures (effectively ageless immortal but horribly radiation-scarred) being far more commonplace. Further, strains of highly (or modestly) intelligent Mirelurks, Fog Crawlers, Tunnelers, Deathclaws, Gators... You name it, if it's been mutated into something humanoid-shaped (bipedal basically) it is often smarter than some humans around.

Let's not forget another Vault... The one on Pandora. The Eridian Vaults don't feature as prominently in the Rookery mostly by virtue of the Eridians themselves being long extinct - mostly, maybe**. Again this dimension serves as a feeder for other weirder Nexus worlds below. It too however has a wide vareity of tech companies that overlap a lot of the ideas and functionality of those found here, and include Sirens - natural Psionics - so there's that aspect. **They're not extinct. They crossbred with humans on numerous worlds, and some of them have made it directly to Carramba.

Another is considerably closer to actual-Canon (let's call that one 'Valve Earth'...) where in Lane is also known as an 'atrocity dealer', with enough conscience to turn the tides against his coworkers and employers. Also of note: this entire project has been in progress much longer than Valve's work on their own games, and will only faintly brush up against the recently-released Half Life: ALYX game. It is not considered in the running for any plot or character development because I don't own it and can't use VR anyway so screw it. However the plan for my own story Repurposed already involved Keenan being captured - which Valve did too, and it wouldn't be the first time I've predicted Valve's story or individual ideas. Any similarities will be coincidental; however, what does appear in canon for Rookery Earth is a lot of the Black Mesa game's visuals and characterizations.

Other, more minor 'variations' include "Dimension Failure" - an already-fallen Earth, with a very mortal - but still Convocation - Lane, without Black Mesa, Aperture, or Vortigaunts. It is nearer X than Rookery in 'finished off before we meet anyone there', though only one known survivor comes from that dimension: Journey Blankenship, a Melissa analog.

Some worlds don't have any form of psionics or mind-powers there, they have their own issues and commonalities to existing corporate types: Augmented Earth, where cybernetics and later nanotechnology and viruses have changed Humanity in ways that are in fact a little too close to the Combine's methods (at least, too close for Melissa to really like), which hooks up only in one specific location, Detroit, and supplies only alternate worlds seeding kids into Carramba High. And then there's the opposite being true, in the Wizarding world, where a few students have made it across dimensions either by accident or concerted effort of pure magic. The rest of their dimension is mundane and not necessarily as advanced as modern real-world Earth. This is where Nash Darnell is the human-born Lane, apt to drift in dreams and be contacted by numerous other of his doppelgangers. Quite a few of those students also head to Carramba.

Twoarth and its attendant Carramba High School is a version of Earth that has not one but two Black Mesas and two Apertures, though whether Armacham exists there is in question, it certainly isn't at the level of technological domination that it was on Repurposed Earth. However, Twoarth is a Nexus World, one which seems to attract all manner of weird to itself. It is after all two Earths, one reversed, slapped together at the Pacific Ocean. One side of it has a Human population while the other is dominated by a vast variety of Furries. While it has time pass... Time doesn't exactly behave the way you'd want it to there. Neither does it pass the same on another Nexus world, Zekira, which has supplied several instrctors - as well as genetics and Yet Another Keenan in the form of Kallah Vahh. Their social structure and level of technology are quite impressive, though they cannot utilize robotics and implants, they have a fantastic array of genetic abilities at their disposal, along with bizarre mutations. Zekira has its own distinct alternate timeline which is specifically 'DragonMasters', and most references to Zekiran characters therefore come from that alternate world, but plenty of outright contradictions and crossovers occur between them all.

A variety of characters hail from some of these alternate worlds, by virtue of multidimensionality already being a thing among most of the settings. Somewhere, a collection of Keenan Lane has appeared... Almost all of this is even possible because of dragons. Once they started flying between and through time... Nothing at all was out of reach.

For the sake of a time line, 2006 is when the Resonance Cascade (on all worlds) and the Synchronicity Event (on Repurposed Earth) happened. On the Rookery in 2027 or thereabouts, Adrian Shephard is let loose and promptly put back into storage (though the Clone Girls story seems to hint someone has been poking around the Borealis... hm.), and the Combine threat is not contained. About this same time, GLaDOS is creating the Color Guard. In the same year on Repurposed Earth, the Combine has already been taken down. When Repurposed Keenan is approached by a dragon and begins the process of creating the Rookery on this other world, it's 2034 on Repurposed Earth. So though the Color Guard was sent by GLaDOS from around 2027 on Rookery/X Earth, the world they went to for their schooling was around 2004 through 2010. And when they come back to the Rookery it's... 2034. Complicating that is Vault Earth's timeline being approximately 200 years into the future in the 2100s to 2200s, as well as Rapturearth's being slightly disjointed into the past, around the early 1900s unless specifically mentioned it's in a different era. I'm so, so sorry. Oh you want a visual timeline?

Honestly it's best just to not think about it. ;)