NOTE: This article contains SPOILERS for Rogue One and Star Wars Rebels
For fans of the Star Wars Universe and it's many legendary heroes, villains, adventures and battles, it was almost impossible to not find the premise of Star Wars Rebels particularly enticing. Where The Clone Wars had helped fill in the gaps between Episodes II and III - a prequel story upon which fans were starkly divided, and amounting to an entertaining, but limited chapter - Rebels promised a new and unpredictable story of the first days of the Rebel Alliance. And in its third season, things have gotten even more interesting, with one character from the most recent Star Wars movie appearing on Rebels just two fictional years before his big screen finale.
But as exciting as it was to see Saw Gerrera's (Forest Whitaker) return teased in marketing, the linking of Clone Wars, Rebels, and Rogue One was only a part of the story. By returning to the planet at the heart of the prequel trilogy (and the rise of the Galactic Empire, and its Death Star superweapon), Star Wars Rebels tied together the prequel films, the original trilogy, Rogue One, current comic books, and the now "Legendary" mythology.
And to make sure that no fan will miss a single detail or connection in the two-part story "Ghosts of Geonosis," we're breaking it all down.
The fact that both Rebels and Gareth Edwards' Rogue One occupy the same time period in the saga led to several easter eggs and overlap between the two, with the role of Saw Gerrera in the latter's story viewed as the most groundbreaking (having been introduced as a Clone Wars character first). Most of the other easter eggs followed a similar direction - elements of the show being hidden or referenced in the film - but Gerrera's return to Rebels promised something slightly different. For starters, this version of the character is actually modeled after Whitaker's on-screen portrayal, as opposed to the younger (and completely different) Clones version. And while that makes Saw's presence on Rebels the most visible link... it doesn't amount to a whole lot more.
The fans of the previous animated series get a bit of fan service with Rex, the Rebels' older surviving Clone soldier recalling his interactions with Saw so many years before. Fans of the film, on the other hand, get to see the "extreme" approach and philosophy of Saw on full display - years before such fanaticism drives him away from the Rebel Alliance and into his own pocket of paranoia on the planet Jedha. It's not the most subtle foreshadowing (Saw wants to torture a perceived enemy based on suspicion and revenge), but it does match who he will become.
Unfortunately, there aren't any mentions of his parenting/mentoring of Jyn Erso or, even more strangely, any of the medical problems which will ravage his body by the time Rogue One begins. The audience is left with only one conclusion: this infamous member of the Rebellion has a rough few years ahead of him.
Evidence of The Death Star
For those drawn in to the midseason premiere of Rebels due to the larger ties to the Star Wars movie universe, this marks the first return to Geonosis... well, ever. But for the devoted fans, it's a repeat visit, since the cast of the show actually arrived at the planet in Episode 15 of Season 2. The episode, titled "The Honorable Ones," saw the team of Rebels dispatched to the planet's orbit to investigate one of several Imperial construction modules left in its orbit. At the time, only debris remained of whatever weapon or technology the Empire was assembling (a device now known to be the Death Star).
In that episode, the Jedi on hand detected that all life on Geonosis had been wiped out, but with a more pressing mission to take care of, never got the opportunity to investigate what the disappearance of the Geonosians had to do with the Imperial construction project. The episode hinged mainly on the uneasy alliance formed by the Rebels' 'Zeb' and the Empire's 'Kallus' (which would grow into a far more lucrative relationship between the two in Season 3), but thanks to "Ghosts of Geonosis," more of the holes in the timeline have been filled in.
Following the trail of Saw Gerrera's team, our heroes are drawn to an unknown power source on the planet's surface - soon revealed to be a shield generator once used to protect something the Empire held of particular importance... likely being built in the planet's orbit.
Existing fans know of the superweapon in question, and its fate. But even if you had only watched the events of the Star Wars story in chronological order (the prequels, followed by the Clone Wars and Rebels), the pieces could be seen fitting together. Way back in Episode II, Geonosis was raised as the heart of the Separatists, with the factories and ingenuity of the planet and its "bug" inhabitants put to work on creating the massive Droid Army. The alliance and its army was assembled under the orders of Count Dooku/Darth Tyranus, following the larger plan of his master Darth Sidious, assembling a force that could militarize, then Empire-ize the Galactic Republic.
At that point in the story, the dream of a moon-sized battle station had yet to be realized. But the concept had been struck between Sidious, Tyranus, and Poggle the Lesser of Geonosis - the plans for which were handed off to Dooku/Tyranus when the Jedi and Clone Army arrived to spoil the party. A full-scale invasion by Republic forces would eventually follow in the Clone Wars series, but the future Emperor had much larger plans for the planet. Once the false uprising had been quelled, and the total power of the Emperor established, the Geonosians were once again put to work in beginning the construction of the Death Star in the planet's orbit... before it was moved to a new location close to completion, and the clean-up began.
For clarity's sake, the arrival of the Rebels cast takes places in 2 BBY, or two years before the Battle of Yavin in the original Star Wars. That's just two years before the Death Star would be officially unveiled to the galaxy through its destruction of the planet Alderaan (only days after it debuted in Rogue One to destroy Jedha City and Scariff's Imperial installation, along with all inhabitants).
Although the timeline of the overall Star Wars universe can get a little fuzzy in areas, Rebels helps clarify that the Empire's guerrilla enemies knew for years before Rogue One and A New Hope that the Empire had constructed some kind of superweapon in the orbit of Geonosis, but with all evidence wiped out - aside from what the Rebels crew had spotted in their first visit to the planet - it was impossible to know exactly what it was. Especially since the last remaining Geonosian who actually witnessed the construction could only depict the Death Star as a circle within another circle.
The Fate of Geonosis
The canonical story of Geonosis and its native inhabitants began in the prequel trilogy, but the darkest chapters exist outside of the films and TV series. Their alliance with the Separatists and construction of the countless Battle Droids immortalized them in all-out combat with the Jedi and Galactic forces, but as the Clone Wars revealed, all evidence of the population had been wiped off of the planet's surface just twenty years later. The explanation for which may have been explicitly stated in "Ghosts of Geonosis", but had been Star Wars canon even sooner.
As established elsewhere (including the recent Darth Vader comic series), the Death Star was only constructed in the orbit of Geonosis for a handful of years, at which point it was moved - still uncompleted - elsewhere, likely to a more remote location... or at least one less directly tied to the war's history to avoid detection by the Rebels. But there was little point to erasing evidence of the Death Star's construction if the scores of aliens who witness it firsthand lived to offer an account to any who came asking.
Not to mention the potential witnesses who saw Palpatine's plan taking shape behind the planet's closed doors. As a result, the Sterilization of Geonosis commenced, with orbital bombardments and chemical attacks used to eradicate the Geonosians en masse - all ten billion of them.
Only the civilization's ruins were left behind for the Rebels heroes to uncover in "Ghosts of Geonosis," along with the aforementioned evidence of the shield generator, and what Battle Droid remained. The episode also revealed the leftover chemicals used to kill the population, although the Rebels were unable to remove them as evidence of the genocide committed (to show to the Senate, which existed up until the beginning of A New Hope). But the characters also found an even more important treasure on the planet: a remaining Geonosian, possessing a powerful secret... and the future of his people.
The secret couldn't be communicated, due to both the crude symbol of the Death Star itself, and the fact that translators apparently don't work for Geonosian language. But the egg containing the last remaining, unborn queen spoke for itself. Since Geonosian Queens are capable of producing an egg every eight seconds or so, the Geonosian protecting her - named Klik-Klak - was right in his belief that she alone could return his people from extinction. The two-part episode leaves the future of Klik-Klak and the Queen ("Karina") a mystery, but fortunately for fans, the rest of the Star Wars universe doesn't.
An we're sad to say... it doesn't end well for Karina.
The planet is returned to in Darth Vader #4, when the titular Sith and the droid archaeologist Dr. Aphra head to Geonosis in search of a somehow-surviving droid factory. What they find is something out of a robotic alien nightmare and, now that we know the backstory behind the creature's existence, fairly tragic. Apparently, the egg protected by Klik-Klak survived until birth. But the sterilization succeeded regardless (perhaps after the Rebels accidentally bombed the air shaft Klik-Klak escaped below), meaning the Queen survived, but was nevertheless unable to create new Geonosian children.
Since the biological imperative of the Queen is hard to set aside - and likely because she was rescued by a creative, resourceful, and committed subject - an alternative solution was concocted. By attaching herself to a mechanical womb instead of an organic one, the Queen gave birth to Droids modified to more closely resemble the Geonosian physiology. It's as unsettling and gross as it sounds, but it's hard to not pity the creature when Vader removes her from said womb and steals it for his own purposes. Even harder, now that fans know it truly seals the fate of any Geonosian population surviving at all.