The beast was chained to a stake in the corner of the pit. Peridot didn't see it right away, due to her and Yellow Diamond's warp pad putting them on a balcony overlooking a rather crude dirt floor sunk into the bottom of the room.
Peridot knew right away this was a corrupted gem. It resembled an animal that Peridot had only seen before in holograms, because of its association with Rose Quartz; a lion. It was huge, colored golden-red, with a shaggy orange mane and glinting red eyes. It also had huge teeth and claws, and looked like it would use them on any gem who came too close.
"This one only recently became corrupted," said Yellow Diamond.
"How?"
"That's not important. We're just using it for an experiment."
Peridot studied the beast. It twisted around and growled at her and Yellow Diamond.
"What gem did it use to be?"
"Not important either. We are studying fusion, and the question here is—"
"Whether a corrupted gem can fuse with a normal gem, and what the effects are." Peridot was proud of herself for knowing the particulars of every experiment Yellow Diamond wanted her to perform. She was one of the diamond's top scientists.
"I trust you know what to do here?"
"Oh, yes."
"Then here is the other half of our amalgam. Aquamarine!"
A door opened in the back wall of the pit; a blue gem slipped in and swiftly shut it behind her. "Yellow Diamond," she said, bowing quickly.
She was one of Blue Diamond's subjects, a magic-wielder. Her flowing cyan-colored dress that swirled around her ankles when she moved confirmed that she wasn't meant to fight up close. It also helped channel her water magic better, or something like that. Peridot just knew she somehow didn't trip everywhere she walked.
Aquamarine caught sight of the beast, now locking its eyes on her, and gasped. She shrank back against the wall, clutching at her dress, smoothing her hair, which was tied into a knot at the back of her head.
"I'll leave you here," said Yellow Diamond, stepping onto the warp pad. "Tell her what to do, and I'll come back when you should be finished." A flash of light, and she was gone.
"What are you…asking me to do here, madam?"
Peridot looked down at the nervous blue gem shivering at the edge of the pit. Aquamarine looked very small next to the huge beast snarling from the other side.
"Have you ever fused, Aquamarine?"
Aquamarine hesitated, then shook her head. "No, madam."
Peridot did not question her further on that. "Do you know how to dance?"
"No—I mean, yes, madam."
"Where did you learn?"
"My…my friend Sunstone taught me, madam. She is made for fusing—"
"I know that. Did you fuse with her?"
"N-no, madam! She just taught me to dance, is all…that's how I know."
Peridot gestured to the beast. "Then dance."
"You want me to—oh! But—it's chained up, it can't move more than a few feet, and—"
"I didn't ask if it could dance. I'm asking you to dance. You said you could. Do it."
Aquamarine swallowed hard. "Madam, I…"
"You can dance. That is all you need to know how to do. You said you could do it. So. Dance." Peridot glared down at the blue gem, hoping she looked enough like Yellow Diamond at her most threatening.
Aquamarine stared with huge eyes at the creature growling at her. It raised a huge paw, gleaming claws jutting out from its toes with no sheath, and swiped at her as much as it could. An orange-red gem glittered in the center of its foot.
Aquamarine took a few shaking, hesitating steps towards the creature. She held out her arm.
And she danced.
Peridot watched her, mildly intrigued. There was something mesmerizing about the way she moved, placing one foot in front of the other, lifting her arms, raising herself onto her toes, spinning—Peridot noticed she was trying to match her movements to the incensed stamping and clawing of the beast. It was fascinating, seeing this elegant ritual juxtaposed with this animal's rage.
Aquamarine whirled in the direction of the beast. Her flowing dress looked like ocean waves.
There was an explosion of light.
Peridot leaned forward. "Oh my…"
The beast had broken free of its chain.
It staggered into the middle of the room, swung its massive head around, and gazed back up at her.
It looked different, that was certain. Its face was notably more like a Gem's, its mane was interspersed with orange and blue, it had two dull red eyes and two bright blue ones, it stumbled on six legs and its front claws looked noticeably more like hands.
The beast tilted its head at Peridot, licking its saliva-dripping fangs. It gnashed its jaws hungrily.
Peridot thought of fleeing.
The beast stepped backwards. It shuddered.
It spoke.
It didn't sound like any Gem's voice; it sounded like the beast's snarling twisted crudely into words. It said something that sounded like—
"I—am.."
"Aquamarine?" Peridot breathed. "You in there?"
"…not…Aquamarine." The beast closed its mouth, swallowed, gasped out:
"Fire Opal."
Peridot had heard of opals before. They were all fusions. She'd never seen one—she'd never seen any fusions before, but she was sure they weren't supposed to look like this.
"How do you know?" She couldn't help but ask, despite the effort it looked like it was taking this creature to talk.
"Wait—don't tell me."
She had a feeling she already knew.
Peridot concentrated on taking notes with her hologram. She technically didn't need to write down what she was able to remember, but it was nice having this. It could also record images, which was useful in this situation. She made sure to get a view of all sides as the creature paced in a circle.
Fear and excitement swapped places over and over inside her. She hoped this thing didn't try to attack her, at least not without Yellow Diamond there.
The familiar sound of someone materializing on a warp pad came from behind her.
"Yellow Diamond! Look—it worked—"
The beast let out a mighty roar.
"Interesting." The diamond stepped forward, appraising what was once a beast and a gem. It was shaking in place, but definitely not from fear.
"She's trying to stay in control, I can see."
"Who is?"
"Both of them, but it's harder for little Aquamarine to keep this thing down. She'll have to keep trying. As long as one of them is in control, they'll stay fused."
Peridot nodded. That made sense. "Is that how fusion works? Like, regular fusion between two gems?"
"It's more like both gems are equally in control, but in certain cases a power imbalance is necessary. When they're both in their right state of mind, of course, it's easier."
The beast, which had been hunched on the ground, trembling, suddenly straightened up, reared up on its hind legs, four forelegs outstretched, and lunged at the two gems on the balcony.
"Stand back." Yellow Diamond held one arm in front of Peridot and whipped out some kind of instrument with the other. She thrust her weapon at the beast, which howled in pain and fell back, landing with a loud thud on the floor of the pit.
"I've destabilized it," Yellow Diamond explained as Peridot looked closer at the beast. It stopped writhing as curious lines appeared all over its body and its limbs began to separate. Soon, there was nothing left of it except two gems, one blue, one red-orange, each sitting in a small depression in the dirt.
"You know how to bubble gems, I presume?"
"Yes, ma'am." Peridot slipped through the gate blocking the staircase into the pit. She reached the gems and carefully enclosed each in a translucent yellow bubble.
"Take these back to the laboratory," Yellow Diamond said. "We will be working with them more in the future.
"I'm also interested in seeing the results of that Aquamarine reforming," Peridot told the diamond as they stepped onto the warp pad. "Will she be corrupted, too?"
"I do not know. You can find out on your own."
Peridot hoped not. She didn't want to have to fight a corrupted gem by herself. She didn't even know how to summon a weapon yet, let alone hold her own in a battle.
"You did well," Yellow Diamond told her, once they'd landed.
"Really?"
"Yes. I know gems above your level who would have fled as soon as they saw that thing. But you can stay calm in a crisis. A very useful skill to have."
"I…thank you, ma'am."
Peridot didn't think she was very good at staying calm in a crisis. But she wasn't about to refute a compliment from Yellow Diamond.
As Peridot locked away the bubbled gems, she thought about Fire Opal. She wondered what the fusion would look like if they were both whole gems.
She wondered about fusion in general. What did it feel like?
She wondered about Aquamarine. She shouldn't worry about her—clearly the water gem had done something wrong. But still, it must be awful being fused with that thing. Especially when…
She wondered, briefly, in the back of her mind, about Sunstone.