It was late at night as Steven snuck down into the Burning Room. After a hectic week where everyone had at least begun to come to terms with the truth about Rose Quartz, aka Pink Diamond, he realized there was someone else who deserved to be told about it. And he knew if he discussed the idea with any of the Crystal Gems, they'd try to talk him out of it, saying it was too dangerous, so here he was without anyone knowing. It was a risk, no question, but his conscience just wouldn't let him rest with the task still undone.
Luckily, there was no need to search through all the bubbled gems, as this particular guest was held in her own special place, where any interference would be instantly noticed. So in the best case scenario, he'd still be in big trouble very quickly, which he tried not to think about as he climbed up to where Jasper was kept.
The other risk he was running was his theory not panning out. Even after what had happened with Centipeedle, he'd hoped that being able to catch the corruption so soon after it started would allow his healing powers to fix it for good, and from what he understood of the process, Jasper's being held in perfect stasis all this time should mean it would still work, if it was actually true.
Once in position, he jumped out, using just a big of his floating power to get to the right position. Finally the moment was here, and there was no turning back, so he took a deep breath and released the captive gem.
Just like with Centipeedle, there was a brief moment where the corrupted Jasper was completely disoriented upon being released, when he could approach her and slap on some of his saliva. Upon that being done, he quickly backed away as she became a bright light, which slowly changed shape. Steven's heart soared as it turned fully into Jasper's true form; he'd been right! And then he remembered that next would come the really hard part.
Jasper's eyes immediately scanned around the room once she regained consciousness, and quickly fixed on Steven. Pure rage engulfed her face as she bellowed "ROSE!" and raced toward him. Steven quickly activated his bubble and bounced away, shouting "Please, I just want to talk!"
Jasper turned around, and seemed to truly take in her surroundings for the first time. "What is this perversion? It's not enough that you refuse your enemies an honorable death, but then you keep them for harvesting? And you called us cruel."
Steven kept the bubble up as he finished his bounce. "It's nothing like that, but that's not important right now. Look, just think for a second. Why would I let you out, and heal you?"
Jasper scoffed. "I learned a long time ago not to worry about why someone like you does anything. The only thing that matters is giving you what you deserve." She launched at him in a spin attack, to which he hopped up to higher ground.
"Here, just look at this!" Steven lifted up his shirt. "Even a Ruby I met once could tell there was something strange about my gem, and that's because it's not a Rose Quartz."
That finally brought Jasper up short. "What do you mean?"
Steven took another deep breath. "I know this will be hard to believe, but it's a Pink Diamond."
Jasper's jaw worked silently for a few seconds, then she glared at him with disdain. "How dare you desecrate her memory like that?" she yelled as she started climbing up. However, this time Steven didn't move, and when she reached him he looked her right in the eyes as he lowered the bubble.
"I hoped it wouldn't have to be this way, but all right. There's one way I can prove it to you: poof me."
Steven barely had time to think at all about what he was doing before Jasper's helmet appeared and came crashing down on his head, which was probably for the best. As the usual smoke cleared she looked down with satisfaction at the gem left behind…until it rolled onto its side and revealed its true shape.
Horror stole over Jasper's face as she tried to take the sight in. Then the Diamond started to roll off the side, and she instinctively grabbed it and jumped back to the floor, where she continued staring at it. "How would she…why would she…this doesn't make any sense!" She went to the wall and started punching it in her frustration, but was interrupted by more voices.
"Okay Steven, if this is about freeing more mutants…" Pearl's voice cut off as she and the other Crystal Gems entered the room. A split second after taking in the sight of a free and healed Jasper, her eyes went to the gem on the floor. "MY BABY!" she shrieked and dove for it.
And with that, suddenly Jasper knew what she had to do. Whatever was going on here could wait, and all that mattered now was protecting her Diamond. She reached the gem just before Pearl and shouted "Don't you touch her!" as she cradled it to her chest. She eyed each of the Crystal Gems in turn as she went on, "I won't fail her again. I'll take you all on!"
The first one to deal with was Pearl, who she easily got past after a few dodges of her spear. Then Amethyst threw a whip around her arm, but Jasper simply yanked her off her feet and backhanded her without breaking stride. Finally there was Garnet, but the increased stakes compared to their last fight lent Jasper a whole new ferocity as she sidestepped every attack and even with only one free arm landed some monster hits of her own. At last she had a free path to the door, and activated her spin attack to race out before they could regroup.
The Crystal Gems were left to stare in disbelief, none of them having any idea what to do from here.