It’s okay to ask for help, you know.
Since negotiations between Peridot and the Crystal Gems are at an impasse (thankfully she’s conceded Steven the use of his bathroom), this episode is all about Steven hanging out with her and gaining her trust.
Specifically, the Crystal Gems have kind of given up on getting any more info out of her and decide to try investigating things themselves, leaving Steven to keep an eye on their “guest”.
Amethyst: Make sure she doesn’t try anything.
Pearl: Don’t worry. She’s harmless without her limb enhancers.
Peridot: I’M NOT HARMLESS!
Naturally, Steven’s a pretty chill jailer. But Peridot has precious little chill.
Peridot: It’s happening!
Peridot: The Cluster!
Peridot: What else could be making that horri- ah! It’s pounding on the Earth from the inside! This is it. This is the end of the world!
Steven: Oh, that’s just thunder.
Steven: Yeah, everything is fine, it’s just thunder. It happens when it rains.
Turns out Peridot doesn’t know much about how Earth works, since things like “weather” weren’t expected to interfere with her mission (and if things like that did arise, she always relied on her “screen”).
Steven: This is just something that happens on Earth. Isn’t it cool?
Peridot’s been in fight-or-flight mode ever since she crashed onto Earth, and since she lost her weapon, she’s just been in a state of constant anxiety (and not just because of Impending Doom, though that certainly is a big factor). She’s sincerely grateful to Steven for explaining the thunder, but she seems to extrapolate a bit much from it.
Peridot: You’re a much more intelligent creature than I initially thought.
Peridot: Yes, much more useful than those clods…Steven! I’ve made up my mind!
Steven: About what, exactly?
Peridot: I’ve decided to share some information with you. […] It’s about the Cluster.
Steven: Wait, you have to tell the Gems, they need to know this!
Peridot: No! I don’t want to talk to them! You’re the only one I need! I could show you now, but I have nothing! My arm attachments, my fingers, my screen, my log! It’s all gone! But all my logs up to date 652 still exist, backed up in Facet 5 of the Prime Kindergarten!
So Steven agrees to take her to the Kindergarten as long as they hold hands the whole time, because he is Steven and of course he’s gonna trust her.
While they’re walking to the terminal-thing, they get to talking about where Steven came from, as you do.
Peridot: You’re some kind of quartz, right? You must’ve been made here.
Steven: Uh, I came from my mom and dad.
Peridot: Are those some kind of rocks? Or another planet?
Steven: Nope. My dad’s from Earth, but my mom’s a Gem.
Peridot: So you’re some sort of hybrid? How is that possible?
Steven: The answer to that is a story I like to call “The Ballad of Rose and Greg”.
Steven is too precious.
It seems like all Peridot really wanted were some visuals to help with her exposition…
Anyhow, she explains that the “Gem mutants” were just preliminary experiments.
Peridot: We were growing them here at this very site, but these were only prototypes for the final product, a singular giant artificial fusion, comprised of millions of Gem shards – the Cluster.
Steven: Peridot, you’re saying there’s a giant mutant Gem the size of the Earth under us right now?
Peridot: Oh, no, when it forms it’ll be much much bigger than the Earth. Right now, it lies dormant, incubating at the Earth’s core. But when it emerges and takes its physical form, it will destroy the planet. The prototypes are already emerging. The Cluster is next. If we can’t get off this planet, we’ve got to stop the Cluster! I thought it’d be impossible, but now we have a chance.
Steven: What is it?
Peridot: It’s you, Steven! Now that you’re filled in, we can get to work.
Steven immediately does his best to disabuse her of the notion that he’s somehow an expert on Earth sciences, and then they get another reminder of an area where the two of them are lacking: Combat.
I certainly appreciate them going all-in on the body horror this time.
Peridot: Can’t you destroy it?
Steven: No, this is all I can do on my own.
Of course the Crystal Gems arrive shortly to take care of the mutants, and this visceral reminder of her shortcomings finally convinces Peridot that maybe she needs the aid of the other Gems after all.
Peridot: Alright, listen up you clo- Crystal Gems. I’ve made up my mind. I have something to tell you about the Cluster.
Until next time…