[Author's note: Although I have had experience in writing before, this is my first fanfiction, so don't judge too harshly, but feel free to leave criticism.
I neither own nor work on Steven Universe, so if I get any details wrong about the show's internal rules or backstory, either those already revealed or those revealed after this story is published, I apologize.
This story takes place after 'Chille Tid' but not necessarily right after; it could take place before or after the Week of Sardonyx, for example, or somewhere in between as-of-yet unaired episodes, at least up to the point where it no longer makes sense in canon.]
Steven woke up. It was about eight, the same time he usually woke up, and he was filled with the same youthful energy as always, but something was different this morning. He had emerged from a troubling dream—not a disturbing dream, not really, just a troubling dream, the likes of which he had dreamt before.
He glanced about the room. Sometimes, one or more of his guardians would be there, sitting and contemplating things while waiting for Steven to wake up. There was no one waiting there today, however; they must have been either out on a mission or doing something inside the temple. So it was Steven's turn to wait for them.
He got up, got dressed, and poured himself some cereal and milk. About halfway through his second bowl, the door at the far end opened and Garnet emerged.
"Good morning, Steven," she said.
"Morning!" Steven replied. "You don't have anything you're planning to do today, do you?"
"Nothing that can't be done tomorrow," Garnet said. "Do you have something in mind?"
"I just want to make sure you, Amethyst, and Pearl will all be here together."
As he said this, the door opened again and Pearl exited; moments later, the same thing happened except with Amethyst.
"Well, I had a good sleep last night," Amethyst said, stretching. "How about you, Pearl?"
"You know perfectly well that I don't sleep," Pearl replied with some annoyance. Amethyst's teasing had had the desired effect.
"This is great!" Steven exclaimed. "Now that everyone's here, I can tell you about this odd dream I had last night."
"Welp, time to go back to sleep," said Amethyst, stretching out on the couch and closing her eyes in preparation of the boredom to come.
"No, it's wasn't like that; this was much more important!" Steven protested. "It was like that dream I had about Lapis. But this wasn't about Lapis…or Malachite, I guess. It was about a Gem I've never seen before."
"And you're sure this wasn't just an ordinary dream?" asked Pearl.
"Of course not! I mean, it started out as a normal dream with me acting as arbitrator between two feuding factions of the Crying Breakfast Friends, but then everything disappeared and I heard someone call out 'help me', except they weren't really saying 'help me', that's just what their emotions were saying, and I kept getting glimpses of this Gem and this location and so I think that Gem is trapped in that location and we need to save her."
"This 'location' you mentioned," said Amethyst, "it's on Earth, right? Because if not, we're not really gonna be able to help her."
"Of course it's on Earth!" said Steven. "At least, it felt like Earth. I mean, I can't really describe it, but I know there's some Gem out there and she needs our help!"
"So there's some unknown Gem out there? Could that be possible?" asked Pearl, glancing a bit to Garnet as if seeking an answer from her. "I'm still not sure how he was able to mentally link with Lapis through his dreams. I mean, Rose didn't have that ability."
"Rose didn't sleep that much, either," Garnet replied. "And Steven isn't Rose. He has healing spit instead of tears, and he can fuse with humans. And although the ability to communicate mentally with Gems outside of fusion is uncommon, it's not unheard of. Future vision is just as rare, but we all know it exists. So Steven," she said, turning back to the boy, "you said this location was on Earth. Do you think you can narrow it down a bit so we have a place to begin looking?"
"I think so. Maybe." Steven scratched his neck. "I can picture it in my mind, but I don't know where it is. But it seemed familiar. Or at least, it felt familiar." He thought for a moment. "The Gem Battlefield! I didn't recognize it at first because the strawberries weren't there in my dream."
"There?" said Pearl. "But I thought we had combed the entire area for any shards!"
"Evidently not," said Garnet.
"Yeah!" said Steven enthusiastically. "We should go there and look for her! …Right after I finish my breakfast," he said, placing another spoonful of cereal in his mouth.
Soon, the warp to the ancient gem battlefield activated and the figures of the four Crystal gems emerged. Bushes of strawberries stretched as far as the eye could see, interrupted occasionally by discarded gem weapons and chunks of stone that did not appear to have formed in the field naturally.
"I know the Gem's around here somewhere," said Steven, "but where are we supposed to start looking?"
"This way," Garnet said matter-of-factly as if she knew without a doubt where the gem was located, which was most likely the case. She led the others across the field to a large rock, weathered by erosion and sunk into the ground. "Here," she said.
"Er…that's a bit big to be a gemstone, isn't it?" said Steven.
"No, she means that the stone is trapped underneath," said Pearl. "They're trying to reform, but there's no room for it."
"Precisely," said Garnet, and she lifted the rock and tossed it aside. There, in the depression it left behind, was a small, yellow gemstone, a little covered in dirt but still shining. Steven ran down and scooped it up.
"Steven! Be careful!" yelled Pearl. "It could have very well fought on the Homeworld's side!"
"Even if she did, we should still help her!" said Steven. "We could—gah!"
The gemstone glowed and levitated from Steven's hand; Steven backed away from it, hiding behind the other Crystal Gems for safety. In midair, a humanoid shape formed around the gem; this shape soon changed to another one, then another, rapidly shifting through what seemed like dozens, then hundreds, of variations. Finally, it settled on one and the now-solid figure descended to the ground.
The new Gem's physical form was slightly taller than Pearl's. It was, of course, primarily yellow-yellow skin, yellow hair, yellow clothes—like her gemstone. Her hair was long and flowing, and her gemstone was set in it to one side like a barrette. It was her dress, though, that was the most noticeable, ornate and a mismatch of styles, as if its creator had spent too much time overthinking its design and tweaking it so that it included every possible decoration she could think of: the skirt was covered in ribbons and ruffles and had so many layers it was if she were wearing a crinoline; the bodice was festooned with a large bow in front and held together at the back by not only tied knots but also several sets of buttons and zippers; the sleeves were poufy and pleated virago style, ending in intricate lace.
The Gem seemed dazed initially and not entirely aware of her surroundings…or herself. She blinked a couple times and then gazed at her newly-formed hands. "I'm…back? I'm back!" she said happily, not noticing the others who just out of her eyeline to her right.
"…Citrine?" said Pearl softly.
The gem turned at the sound of her voice. "Pearl!" she exclaimed, then rushed to her with open arms to embrace her in a large glomp.
"Er, hi, Citrine. Good to see you too," said Pearl awkwardly.
Citrine let go, then noticed the tall, dark-red Gem fusion to the side. "Garnet!" she cried, tears forming in her eyes. She ran over and gave her a hug as well. Then, in the middle of that, she noticed the short purple Gem who was standing beyond her.
"Gah! An Amethyst!" she shouted. She panickedly clambered to the top of Garnet's head, who, to her credit, did not seem to mind, even as Citrine's impractical dress fell down and draped in front of her face.
"Don't worry; she's with us," Garnet said.
"Oh." Citrine climbed back down and approached Amethyst. "Nice to meet your acquaintance." She held out her hand in greeting. Amethyst gingerly shook it.
Citrine turned back to the more familiar Gems. "So, I take it we won against the Homeworld in the end? I hope?"
"Well, yes," said Pearl, "but the vast majority of the Gems on our side were lost in the end. I mean, we thought you had been one of the casualties before today."
"But how about Rose? She wasn't destroyed or captured by the Homeworld, was she?"
"Er, no. She was one of the few members of the rebellion who were saved." Pearl had said the truth, though she had left out certain recent developments and had as such was most likely giving Citrine an inaccurate view of how things currently were. The four Crystal Gems were all aware of that, but none had the courage to inform Citrine of it yet.
"Well, that's good," said Citrine. "So, how long was I out? One hundred, two hundred years?"
"Over five thousand," said Garnet.
"Really? Wow," said Citrine. "I guess I lost track of time after the first few decades. Though I probably should have figured it was longer, what with all these strawberries having grown. Does it take that long for strawberries to grow? I don't have a really good grasp on how long it takes things to happen naturally on this planet.
"Oh, and you have a human with you!" she said, the first time that she had actually acknowledged Steven's presence. She walked up to him and, without any regard for his personal space, started examining him. "Doesn't seem to be fully-grown, though," she said, lifting his arm. "Why do you have an adolescent with you?"
"Uh, that's a long story," said Pearl, concerned about Steven's discomfort but not wanting to call out Citrine's behavior after she had spent so long in her gem. Amethyst, on the other hand, found it amusing.
"Their textiles have come a long way," remarked Citrine, grabbing at the front of Steven's shirt. "The fabric and stitching on this garment is—"
She stopped suddenly. Lifting the shirt had revealed Steven's stomach and, more importantly, the pink gem that was set in it.
"What…why does this human have a gemstone? Wait, is this…is this Rose's gem?"
"Er…yes," said Steven nervously.
Citrine let the shirt fall back down and, for the first time, looked Steven in the face. "Then where's Rose?" She suddenly grasped his shoulders and shook him. "Who are you?"
Steven was too scared to respond.
Citrine twirled around, a look of terror in her eyes, desperately seeking an answer from the other gems. They, however, tried to avoid eye contact. They had had trouble coming to terms with the answer themselves, and they had been there at the time; none of them wanted to relate it secondhand to someone who had been absent for the past five millennia.
"Who is he? Where's Rose?"