I have to admit, as of now, that I have in fact entertained the concept of this pairing for a while, but I wanted something concrete established in the canon of Steven Universe before I got serious about shipping it. Though the episode "Too Far" ostensibly leaves a great deal of gray area on the matter, I just feel too excited after watching it to not slip out of the gate now.
This oneshot also plays with the fan theory that Amethyst is going to go corrupt at some future point in the series; the implications herein are that between "Too Far" and that such event, Peridot and Amethyst have become (more or less) an item, or at least were beginning to realize their feelings. Before getting on to the story, I'd like to also note that the song Peridot sings the refrain of is "I Know You're Out There, Somewhere" by the Moody Blues, though she alters the lyrics a bit so they match the circumstances better. I highly recommend listening to it while reading this; it deeply accentuates the atmosphere of the story.
Copyright for Steven Universe belongs to Rebecca Sugar and Cartoon Network, and "I Know You're Out There, Somewhere" of course belongs to the Moody Blues.
"Guys, guys!" Steven runs from the Burning Room out into the Beach House. "Garnet, Pearl! Peridot! Amethyst's gone!"
The older Crystal Gems came running as soon as they heard Steven cry in distress, but upon receiving this news they are drawn to a speedy halt.
"Gone? She can't be gone! Garnet, you bubbled her gem the moment we caught her! How could she -" Pearl slows her panicked rant down for a second as she glances down at the young half-gem before her. "Steven, y-you didn't release her gem, did you?"
"No, I swear! I came down just to look at her, and – and maybe talk to her gem, but I know better than to take her out, honest!"
"Oh, this is no good! A newly corrupted gem on the loose, and we all know what she was like before this happened! There's no telling what she might do!" Gasping, Pearl grabs at Garnet's arm, "She could set the house on fire!" Gasping again, she protectively snatches Steven up, "Or she could try to murder Steven in his sleep!"
"Pearl! Calm down," Garnet interjects, fiddling with her visor. "We need to ask Peridot. She knows where Amethyst is."
Pearl and Steven stare at Garnet for a moment, before Pearl lowers her charge to the floor. Holding hands, the two proceed to follow after their leader.
/
The Crystal Gems locate Peridot, huddled up on the porch, gazing out at the surrounding beach shaded by early twilight. She is murmuring something which sounds a trifle melodic, though her tone is so quiet that any interpretation must settle on odds of 50/50.
"Peridot!" Garnet addresses her, not aggressively but with enough sternness to make the green gem jump. "Where is Amethyst's gem?"
Peridot gapes upward, intimidated by the fusion now towering over her. Her eyes are wide, and bear a moisture comparable to condensation dripping from a water bottle which recently spent time in the fridge. Steven's heart goes out to her when he sees she's been crying. Garnet really could be a little more sympathetic, with special considerations made for the circumstances.
"I – I don't know what you're talking about!" The cornered gem replies, eyes now playing an alarmed game of jumping jacks.
"Don't lie to me, Peridot!" Garnet replies, becoming impatient. "We can't risk Amethyst getting loose while she's like this; you need to -"
"Garnet, please! Can't you see she's scared?" Steven latches onto Garnet's calf while glancing at the smaller gem, now shielding herself from what seemed to her an onset of the fusion's wrath. Feeling Garnet relent a bit, he then explains, "We're not mad at you, Peridot, we're not." Here a bit more authority comes into his voice, as he looks up at both the older gems, neither of whom attempt to challenge his assertion. "We're just worried. If you know where Amethyst is, can you please tell us?"
Though she is calmed by Steven's compassionate alternative to interrogation, Peridot is albeit reluctant to confide. The terms on which she stands with the other Crystal Gems have come a long way, but she still is not nearly as easy around them as she has become with Steven... or especially Amethyst.
"Please?" Steven indents.
Resigned, Peridot finally pulls a bubble-encased purple gem out from her own, letting it hover above her hand. "I just – I just didn't want her away from me," she mutters, her explanation seasoned with defeat and pain.
"Peridot," Steven murmurs sympathetically, slowly making his way over to and sitting down beside her.
"Peridot, we all miss Amethyst, but that doesn't make it alright to just take her out of the Burning Room," Pearl scolds, not unkindly. "If just one thing went wrong, and she escaped -"
"I know that, Pearl!" Peridot's defences rise again, "Do you seriously believe my sense of reason has become faulty in all this?" Her voice holds vehemency but her glistening eyes do not bear quite as strong a hold on logic as her words.
"Well, no, that's not exactly what I meant -" Pearl objects.
"Yes it was!" Peridot snaps back. Steven's presence beside her proves a fortunate commodity in the heat of the moment, for had he not been able to reach out in time the bubble bearing Amethyst's corrupt gem would have been dropped to the ground below.
"Hey! Peridot, be careful!"
"Enough!" Everyone pauses in response to Garnet's order. "Pearl is right, Peridot. The Burning Room is the safest place for Amethyst's gem, until we can find some way to help her. Believe me, I understand how painful this is for you, but you have to trust me on this."
Peridot glances with hurting eyes at the bubbled gem in Steven's hands. She is about to nod, after a moment, when the young hybrid speaks up.
"Wait, Garnet," he hands the gem back to Peridot. "Can't Peridot keep her just as safe inside her gem? She's done great so far," he draws from what he's observed; he'll personally allow the temporary misstep he thwarted to go uncounted. Peridot was under stress due to Pearl's fretting, after all. "Please, she just wants to be close to Amethyst."
Garnet begins to object, but Steven continues. "What if Ruby or Sapphire got corrupted somehow? Wouldn't the one that wasn't corrupt want to keep the other with her, all the same?"
Garnet is silent. She can sense a ponderous mood shift in her two halves. Hard to argue with that.
"Peridot... Can we count on you not to de-bubble Amethyst, without exception?"
Having her integrity questioned, even mildly, is a pill Peridot has no hope of acquiring the taste for, but she nods, nonetheless.
"Very well then. We'll leave her in your care."
Between Peridot's surprised/grateful smile, Steven's "Thanks, Garnet!", and Pearl's "Garnet, are you absolutely sure?" the leader of the Crystal Gems just smiles understandingly at the green gem, before leading Pearl back inside and motioning for Steven to join them.
"Can – can Steven stay with me a little longer?" Peridot cautiously requests. She's been granted so much already, this might be... what was the phrase Steven taught her? "Looking the gift horse in the mouth" or something of the sort. She is relieved when the fusion nods, before closing the door.
"You're sure you don't know how to fix her, Steven?"
"Yeah. For some reason my mom's healing powers never worked on corrupt gems. But Pearl and Garnet think I might be able to do something, someday," he offers.
Peridot is not as cheered as he'd hoped, however. "But you don't know when."
"Well... no."
"It figures." Peridot looks down at the purple gem, still bubbled, in her grasp. She and her companion are quiet for a few minutes, both pensively regarding the immense loss which Amethyst's corruption has inflicted upon them. Eventually she can be heard to murmur, "I just want you back."
Steven would not have bothered to override his own tears, gradually drizzling down his face, but his compassionate urge to comfort sets in again when he sees the bubble encasing Amethyst subjected to a notable sprinkling. To try and keep his friend busy with conversation, Steven inquires, "What was that song you were singing when we came out? It sounded really nice."
"Hmm? Oh, just something I heard on that music disseminator of yours."
"The radio?"
"Yeah, that. It just seemed to fit the situation."
"Do you remember the lyrics?"
"If those are the words in the song, then yes. A Peridot's always good at processing information."
"Well, can you sing it now? If it's alright with you, that is. I'd like to hear you sing."
"Well... alright then. I'll sing the part I think symbolizes the situation the best." Taking a deep breath, she recollects the melody, and begins, her downward gaze focused on what now can be described as her "charge",
"I know you're in there somewhere,
Somewhere, somewhere,
I know you're in there somewhere,
Somewhere you can hear my voice,
I know I'll find you somehow,
Somehow, somehow,
I know I'll find you somehow,
And somehow you'll return again to me."
When the spell of the moment has ebbed, Peridot glances up from her charge, to the hybrid beside her. There are stars in his eyes as he whispers, "Beautiful."
"Thank you, Steven." She smiles a bit. New to singing overall, it pleases her to know she's caught on so fast. She sighs again, soon after. "I hope you'll figure out how to heal her, some day soon."
"Me too," he replies, clasping his hands together. He tastes the spit, ever forming in his mouth. Why applying it to Amethyst after she was poofed didn't work, he only wishes he could understand. For the umpteenth time he questions why this had to happen to his "fun mom"/sister-figure. Why they weren't able to stop this from happening. He keeps his own miseries over the matter in silence, however. He may have known Amethyst much longer than Peridot, but the relationship the two short gems came to share was like that of his parents, or Ruby and Sapphire. That kind of love is to be treated as sacred, after all; even a ward's love cannot interject.
Steven looks up at Peridot again. In the short time in which he phased out there, she has resumed singing quietly, holding the bubbled gem close, but careful not to disrupt the encasing. He is smiling sadly at the sight, when something catches his eye.
"Peridot, look!"
Peridot stops singing, and looks down in alarm. For a second they are both worried that the apparent increase of luminescence inside the bubble means some sort of trouble is arising, but it is gone just as suddenly as it was there. Both stay silent, on alert. Whatever that was about, it has passed.
"That... was weird," Steven states.
"Amethyst?" Peridot questions, all of a sudden.
"Peridot? What's wrong?"
Nervously, the green gem replies, "I don't know. I – my senses must be malfunctioning. I just hallucinated that Amethyst's gem shot this warm energy through me! I – I must be going crazy," she submits.
"Hmmm... Maybe not." Steven supposes. When his friend turns her gaze to him again, he says, "Maybe what happened was, she was trying to let you know... she misses you too." Though Peridot looks unconvinced (how can a corrupt gem, especially a bubbled one, communicate like that?), he adds, "And maybe that she also likes your singing?"
With the passing of a few beats, the two smile. Improbable though the idea may be, the sentimentality of it ultimately wins out. And if there is some way that Amethyst can "hear" Peridot, then she most certainly is not going to stop singing those words of love and determination.
The End.
AN: The neat thing is, what inspired me to ship this pairing in the first place was a necklace of mine that just happens to feature a pattern of amethyst and peridot stones! Also, two matching tennis bracelets, each bearing one of the gem types. Well, now all we have to do is wait and see how close this story is to what will actually happen! :)