"Weiss? Weiss! Can you hear me!? You need to get out of there now!"
Weiss looked back toward the pier. The ship was waiting for them. Salem and her Grimm were closing in. This was the last moment. If they were going to do something, now was the time. She opened up her scroll.
"Sorry Winter. Someone's got to do it."
"Weiss, no, I'll-"
Weiss cut her off, closing the scroll and throwing it away. "This is it, I guess." She turned to the others with her. Ironwood grimaced, but gave a firm nod. Penny gave a sad, firm salute. "Right. Let's not waste any more time."
"Follow me." Ironwood started running, leading the two girls to the vault.
Once they reached it and started heading down, there was nothing to do but wait for the elevator to finish its descent. This was the first time Weiss had ever seen one of the vaults. It was bigger than she'd expected, and she had been expecting a lot. The word that came to mind was vast. She wondered if the other vaults looked anything like this one, not that she would ever get to see them now. She knew there was no going back.
"General Ironwood..." Penny began, quietly. "What do we do once we get there?"
Ironwood was silent for a moment, then let out a long sigh. "Never mind that. Just keep someone with a good heart in your thoughts. Winter, Ruby, whoever, but don't let your mind stray. After you've opened the vault, Miss Schnee will destroy the relic."
Penny looked to Weiss. "That's what I don't get. Why do you have to do it?"
"Because, Penny, the Staff of Creation only answers to each person once. I have already used it, and it doesn't seem to answer to the Winter Maiden. I suspect that it's because a previous Winter Maiden used it as well..." The elevator had reached the bottom. "Well, it's time to get to work."
As soon as the door opened, Weiss and Penny raced for the vault. Penny reached it first, placing her hand onto the great gate before her and channeling her power into it. Weiss stood in awe as the door lit up and began to fold away into itself. But the moment she could see enough of an opening, she rushed through. Into a strange realm of water, sea life swarming around a small bubble of air where the Staff of Creation awaited. How far beneath the surface they were, she didn't know. Whether this was a pocket dimension for the relic alone or some unknown part of Remnant somewhere, she couldn't know. She reached out and took the Staff of Creation in her hand.
"Alright... time to make something good." She knew what she wanted, and it began to form even as her mind chose the specifications. A sword, like her sister's saber, made for cutting, but with a catch. She wanted a sword that could only damage one thing. A sword that could destroy a relic. She opened her eyes to see her work. "It's perfect."
The vault filled with the sound of someone bashing down the door to the elevator. A scream of defiance as they launched themselves downward to where Penny and Ironwood stood waiting. They prepared themselves for battle, to defend Weiss long enough for her to destroy the relic. Weiss didn't look, she needed to focus as she took hold of the weapon she'd created.
"Down there! Go! Take Weiss!"
Weiss' snapped around, shocked to see Winter storming towards her. "Winter? Wha-"
Winter grabbed the sword and ripped it out of her sister's hand. She shoved Weiss back towards Penny. "GO!"
Penny didn't argue, scooping up Weiss and hopping off the platform. She angled herself downward and boosted herself faster and faster down, rocketing towards the bottom of the abyss. Before Weiss could even properly struggle against her captor, she saw a small hole appear far below them, like someone before them had smashed their way out of the vault.
They burst out of the bottom of the floating city and into the sky filled with Grimm. A flurry of swords and lasers blasted away anything that drew too near as Penny flew them further and further from the city, closer and closer to safety. Weiss wanted to go back, to stop her sister from taking her place. Atlas had flown up so high into the atmosphere in so little time, but the Grimm... she could see the Grimm were still following it. Salem was still following it. No, there was no going back now. They needed to keep moving forward, and faster. Weiss put all her focus into placing glyphs in Penny's way, ones that would speed her up as they made the distance between them and the floating city greater and greater.
Then the city disappeared. In a single flash of light, the entire city vaporized.
"Winter..."
The Grimm surrounding the city vanished in the ball of flame, enveloped by the explosion caused by the destruction of a relic. Mantle would be saved, and all the people evacuated from Atlas would be saved. But Winter was gone.