Our story begins mere moments following the appearance of the Temple Ship. If this were a cinematic cutscene, then players would have noticed the first hints of divergence right after Central Officer John Bradford addresses doctors Raymond Shen and Moira Vahlen, letting them know that... "If you two have any more bright ideas, now's the time."
This simple comment kick-starts a montage set to YouTuber LittleVMills' cover of the Deus Ex: Human Revolution. We would see glimpses of the hustle and bustle taking place inside the most prominent XCOM installations across the globe, including the organization's headquarters underneath Cheyenne Mountain, which is where the aforementioned trio are stationed. These moments are ones that you, as gamers, have likely seen countless time before in both movies and video games; shots of soldiers kitting up, looking at pictures of their loved ones, and hugging and / or kissing a friend. But it's the ones that take place within the depths of the "ant farm" that is Cheyenne Mountain that might make for the most noteworthy. Following a brief segue into the base's cybernetics lab that shows a person stepping into a which then seals itself shut around them like a set of Iron Man armor, things would cut to the hangar, which is seeing the most traffic out of any other on-site "facility."
As XFS-105s launch in the background one after another, soldiers are racing to secure themselves a seat aboard one of the few remaining Skyrangers. At the center of it all though is a much larger, unidentified dropship. Suddenly there comes a shout from behind, and all foot traffic stops dead. Heads whirl around en masse to look for the source of the commotion. Once people's eyes catch sight of Annette Durand (aka The Volunteer), Anna Sing (who has been given an appropriate Asian makeover), Mattie "Alecto" Hawkins, Nubia "Megaera" Tariq and Fatima "Tisiphone" Tariq all being followed by nineteen other XCOM operatives wearing "chunkified" armor and hefting man-portable directed-energy weapons, people step back to allow them to board the large VTOL.
From here things would skip forward in time thanks to a brief transition back to the holographic geoscape that Bradford and the others are looking at. When we catch back up with the Isegrim, we see from Big Sky's point of view hundreds of shimmering lights encroaching upon the Temple Ship from practically every direction. "Central this is Big Sky, you're not going to believe this." "Oh I just might, Big Sky," replies Bradford. Things would then zoom in to the source of some of the lights. It turns out that not all of them belong to Skyrangers and Ravens, but various other craft from the council nations, like F-16s and V-22 Ospreys. (At this point, were this author feeling more "with it," he would go into detail about a conversation that Bradford has with the man leading this particular charge from one of the Ospreys -- namely U.N. General Peter Van Doorn. But he's not, so you're just going to have to make something up.)
And then the shit hits the fan. Despite what Bradford said about humanity's arsenal not being able to make a dent in the Temple Ship, that doesn't stop whoever's on board from deploying a massive swarm of Seekers to impede their progress. You've seen Independence Day, right? The aerial battle that erupts between humanity's warplanes and the aliens' technorganic monstrosities is very similar to one of the most iconic segments from that movie! But the author starts to digress. As this battle rages on, a good majority of the VTOLs manage to break through the Temple Ship's air defenses and subsequently deposit their payload of soldiers onto the surface of the gargantuan alien vessel. Several, however, are destroyed; either while in the process of touching down or during their offloading period.
What comes next is yet another massive undertaking for humanity's warriors, as their force of roughly 120 seasoned fighters (who wear everything from traditional modern day special forces gear to Titan Armor to Mechanized Exoskeletal Cybersuits) takes on the Temple Ship's crew of over 1,200! It's a segment that's very "Michael Bay" in every aspect, and it ends with the remaining humans storming the bridge and coming face to face with the Uber Ethereal and his cadre. At this point the music that started off this whole thing ends, and the audience (if there was one) is left to listen to the surreal sounds that accompany the next scene. (Please stop watching after the 47 second mark! What happens next in that video does not reflect what happens next here!)
Annette and her fellow Psi Operatives have had enough. After giving Van Doorn, Sergeant John Carlock and Private Glenn Friendly instructions to join their fellow soldiers in securing the room that they just entered from, they commit to an all-out assault on the Uber Ethereal using their vast array of Psionic abilities. (The battle is something that the author literally cannot describe. All he can tell you is that it's short and very Matrix-like, with lots of jumping and dodging while scenery explodes in super slow motion as stray Psionic attacks collide with it.)
With a scream that rattles the very foundations of the Temple Ship, Annette shatters half of the Uber Ethereal's mask with a Psionic attack identical in every way to a Kiai from Dragon Ball. Purple, bio-luminescent mist billows from the hole, which the Uber Ethereal attempts to cover with one of its four hands. The others, which attempt to project a Null Lance, are pinned down through invisible, telekinetic hands projected by the three Furies. "This is not your path!" The Uber Ethereal cries. "Not your purpose! You need our guidance to hone this power! Without us, what are you?!"
Annette exchanges a significant look with her sisters, then glares back down at the writhing creature. She says one word - "Free" - before obliterating it with another Psychokinetic Strike. And here, my players, is where things really divert from canon. The energy released with the Uber Ethereal's death is sucked into the over-sized Ethereal Device that resides at the front-most portion of the Temple Ship's bridge, but it does not stay contained there. It dances around the liquid-like core and then rebounds on Annette and the Furies in the form of writhing tendrils made of pure energy. Another such tendril attempts to embed itself in the forehead of Anna Sing, but for whatever reason she is able to fend it off with a hastily erected Telekinetic Field. Just then Van Doorn and several others arrive to investigate. "Go!" Anna screams to them before deflecting another tendril with Neural Feedback. "Get out of here, while you still can!"
Van Doorn takes one look at the other women - who all are standing stock-still, their heads thrown back, their mouths agape, their eyes glowing purple but not staring at anything - and then nods. "You heard the lady, it's time to go! All forces, this Van Doorn, we are pulling out! I repeat, we all pulling out!"
But wait, it gets worse.
"Axis has failed," says Annette and the Furies as one. "But we have determined that this species is indeed worthy of nurturing. We shall now deploy the Second Wave."
"Oh, fuck me." Van Doorn says.
Alien ships, dozens of them, from Scouts to Battleships begin "phasing in" all around the Temple Ship. With the camera tracking Van Doorn as he runs pell-mell toward the evac zone, we watch as the ships orient themselves and begin opening fire upon the human craft outside. (The author advises you to watch https://www.youtube.com/watch?v=j-1FjrvUH3A to get a good idea of the type of ass-kicking that our heroes receive at this juncture, before Van Doorn is able to miraculously make it aboard an Osprey and depart the scene with roughly a dozen other allied VTOLs hot on its tail.)
Back at XCOM headquarters, Bradford sinks to his knees in despair. Similarly, all pretty much everyone else can do is watch in horror as the massacre unfolds. Even the various commanders of the world's most prominent XCOM installations that Bradford is currently in a video conference with appear to be in varying states of shock. Of them, one appears to be a tad more panicked than the rest. "Central, this is Installation Kaduna! Radar is tracking multiple inbound signatures! More than we can count, headed straight for us! Please advise!"
Bradford doesn't need to spin to globe to see what the man is talking about. Installation Kaduna is the largest of the three XCOM facilities in Nigeria, which, for the aliens, was practically within walking distance of the Temple Ship. Kaduna may have had a reputation for getting lucky when it came to collecting "assets," but he knew that not even the likes of Martin Herbert and William Rizer - Kaduna's top-two fighters - could hope to lead a successful counter-counter-attack against an entire Assault Carrier's worth of invaders.
"There's no way that you boys can repel a force of that magnitude. Give the order to evacuate; get the hell out of there, Mal!"
Bradford glances over at the technician, then back up at the Geoscape. He hadn't seen it before in his haste to provide orders. It's not just the installations in Nigeria that this new batch of aliens is going for, it's all of XCOM. The organization has been compromised on a global scale.
"My God. How long until they reach us?"
"Less than 30 minutes."
- - -
Players, this is where you all are when general quarters is announced.
Harold Thatcher? You're medical bay, helping oversee the recovery of several dozen wounded soldiers.
Erin Wynne, Manaia Enoka and Jacob "Dallas" Jackson? All three of you are in the mess hall.
William "Gears" Achilles and Johan "Heimdall" Ræder? Both of you are in the Foundry, working to repair the latter's Guardian-class MEC that had sustained significant damage in a battle against a Mechtoid some weeks back.
Natalie "Harrier" Hashimoto? You are on the cusp of being released from the Genetics Lab with all your shiny new Gene Mods installed.
Take note that I have very specific plans regarding when, what and how many of the enemy is going to attack, meaning that none of you have permission to make them jump the gun and show up early. Understood? Good! Welcome to the apocalypse! There is no posting order.