The following contains spoilers for Andor season 2, episodes 4-6! Turn back now if you're not up to date!
Andor season 2 has introduced a curious material – rhydonium. It plays a crucial part in a plot hatched by Saw Gerrera, which Wilmon Paak has unwittingly found himself dragged into, unable to leave until the plan is complete.
But what is rhydonium, and where has it come up in Star Wars before?
Well, it's a type of starship fuel, and it's best known for being extremely volatile. As you can see by how much care Wilmon takes when handling it, it's explosive, and its fumes are dangerous to inhale. That's why the rebels have to practice their plan so many times before it's safe to carry out for real.
Rhydonium's toxicity doesn't stop Saw from breathing it in on purpose, though, declaring the fuel is his "sister" (though as Clone Wars fans will know, his sister was actually named Steela, and she died many years ago on the Star Wars timeline).
Wilmon also has a go at breathing it in, and he seems to feel its effects pretty much instantly. This might explain why Saw needs a device to help him breathe by the time of Rogue One.
Rhydonium factors into stories seen in The Clone Wars and Star Wars Rebels, and it even featured in The Mandalorian, too, when Din Djarin and Migs Mayfeld stole a transport full of the stuff and had to drive at a certain speed to be safe (too fast and the rhydonium would explode, too slow and they could be attacked by pirates).
Wilmon and Saw ultimately carry out their plan without any issues, though rhydonium's long-term effects on Wilmon – if any – remain to be seen.
Andor continues weekly on Disney Plus, and you can keep up with our Andor season 2 release schedule.
For more, check out our guide to all the upcoming Star Wars movies and shows for everything else the galaxy far, far away has in store.
