Andor season 2 premiered on Disney+ on April 22, 2025. However, with three episodes being released every week, the show is already done with the first half in its second week. Delivering fast-paced and anxiety-tinged events as tensions intensify across the galaxy, episodes 4-6 filled in a crucial part of Saw Gerrera's (Forest Whitaker) backstory.
The radical Rebel leader was first introduced in the fifth season of Star Wars: The Clone Wars and he's been featured in other projects like the live-action Rogue One. However, Star Wars has yet to give a detailed look at how Saw became what the franchise describes as "the original Rebel."
Fortunately, the latest episodes of Andor season 2 filled in some parts of Saw's backstory. Episode 5 of the season, in particular, revealed how Saw became addicted to Rhydonium and how the dangerous chemical became a significant part of his eventual physical decline.
What is the Rhydonium in Andor season 2? Explained
Andor season 2 introduced a mysterious material called Rhydonium, a type of starship fuel. However, it's not a typical fuel because it's known for being incredibly volatile and corrosive. Handling Rhydonium takes a lot of care, as seen in how Wilmon (Muhannad Ben Amor) takes extra care in handling the fuel in the series.
Rhydonium in Star Wars is explosive, but that's not the only harm it brings. Its fumes are also dangerous when inhaled. Even a small leak can burn someone's lungs from the inside out, as Saw claimed in Andor season 2 episode 5. Like how Wilmon takes extra measures when handling the fuel, rebels also have to practice and hash out their plan over and over again before it's deemed safe to carry out.
Read more: Andor season 1 recap
Andor season 2 explains Saw Gerrera's lung damage and his Rhydonium immunity
Despite the volatility and the danger that Rhydonium brings, Saw Gerrera didn't care—he even deliberately inhaled the fumes to get high. It's also not his first brush with the fuel. In season 2 episode 5 of Andor, Saw notably called Rhydonium his "sister" and explained how he got exposed to the toxic gas back on his homeworld of Onderon.
He survived when most of the prisoners died, and he owed his survival to embracing the pain caused by his Rhydonium exposure. Saw also described to Wil how the high he gets from inhaling Rhydonium feels like the sensation of freedom, and even encouraged him to give it a go.
Breathing in the toxic fumes made them feel the effects pretty much instantly, but the Rhydonium didn't seem to harm either of them so far. However, Saw's supposed immunity from the effects of inhaling the toxic gas isn't going to last very long.
Andor is set before the film Rogue One: A Star Wars Story; specifically, season 2 takes place four years before Rogue One. With Saw already outfitted with mechanical lungs and an oxygen mask in Rogue One, it's easy to pinpoint the cause of his physical decline from what was seen in Andor.
By the time of Rogue One, Saw had already been exposed to Rhydonium for years, and it must have eaten away at his lungs from the inside out, leading him to rely on mechanical lungs for survival.
Catch Andor season 2 streaming on Disney+.