Cassandra ran her hands through her hair as they approached the pillar rising out of the ocean known as WoGoRPA Island. Between Theo hacking the cameras and Raven making the guards sick, it was almost impossible for their approach to be noticed. Nevertheless, she kept her eyes focused on the sheer cliffs, ready to fire her sniper rifle at the slightest bit of movement. She had maintained Haruspex as best she could, but she would feel a lot better working on it with Theo again.

"You still up for it, Second?" Yin asked again.

Shinobu laughed softly. "At this point, do we have any other option? How long have I had to change my mind?"

"Doesn't matter. There's still time to change it."

"You're both right," Cassandra said absently, adjusting the set of thruster rings on her hip. They remained silent as they glided along the placid ocean and dropped anchor by the cliffs. Once the boat was secure, they leaned overboard and waved at the orcas, signaling them to wait for a moment. The animals merrily clicked and whistled as they swam around the boat. One allowed Yin to stand on it while she concentrated with her hand on the cliff some distance away. She thanked it once she was done, and the orcas dove out of sight until their next role in the plan.

Shinobu started slightly as her Sisters simultaneously kissed her cheeks and hugged them in return. "I love you both so much." She ascended the cliff with an ease befitting a member of the most mountain-dwelling Human race before propelling herself over the ocean. Her muscles abruptly ballooned in size, her body hair thinned out while the hair on her head lengthened, and two large horns sprouted from her head. A good number of teeth appeared in her mouth as her four short tusks grew long and pointed. Her tunic seemed to disappear into her blue flesh, revealing a tiger skin loincloth that grew as she did.

She crossed her legs as if sitting in midair and stopped before she hit the water. Hovering behind the boat, she leaned forward once her transformation was complete, the vertical third eye on her forehead opening as she peered at her Sisters. "Looks good," Cassandra said, searching Shinobu's red-speckled green irides. "You ready?"

After the anchor was raised, Shinobu nodded and extended her hand for her Sisters to jump on before flying upwards. Cassandra and Yin disembarked onto the ramparts as Shinobu continued to ascend, roaring to announce her arrival. Landing with an earthshaking crash, she held her hand out and caught the enormous spiked kanabo that erupted from the ground. Yin finished their dramatic entrance by snapping her fingers, blowing up part of the cliff and collapsing the wall underneath it. "Badababoom."

Sirens immediately went off as Cassandra and Yin ran in different directions. Cassandra only advanced when her way was clear of employees, not wanting to leave any clear evidence of foul play. Mysterious gases and explosions could be chalked up to the mythical creature that appeared out of nowhere, but battle wounds wouldn't be as easily dismissed. As she had suspected, the guards were too distracted by the building-sized oni tearing through the facility than checking every nook and cranny for other invaders.

She eventually made it to an unmarked door in the middle of the staff quarters. Knocking in a specific way, she slipped inside when the door briefly opened and swept Theo up in her arms, swinging her back and forth. They tightly squeezed each other, Cassandra laughing tearily while Theo cried with happiness. After firmly kissing Theo's forehead, Cassandra set her down to get a better look at her. While thankfully not as emaciated as she was before, she was still skinnier than Cassandra would have liked her to be. A light burn scar covered part of her left arm, but it looked like it wouldn't be permanent. "You've grown."

"Obviously!" Theo giggled, rubbing her face. "What did you think I was doing? I'm almost as tall as Raven!"

"Theodora has grown 13 c-"

"Thank you, Raven. May I?" Cassandra lightly stroked Theo's hair, admiring her new hairstyle. "You look amazing."

Theo hugged her again. "Are you keeping this look?"

"Only until we're done with Impel Down. Ready to go?"

"One sec." She inserted her artificial hand into the door of a small safe. "They let me keep this once I gave them the old AIOLOS design, and they stopped trying to get inside after the first five safes melted down."

The door opened to reveal several cans and boxes of food along with a cylinder slightly larger than her head, and Cassandra knelt down to get a better look. "Is that HELIOS?"

Theo nodded proudly. "Yup! I have enough tetratide to get it started, but it needs SELENE to work properly and I can't build that without Alexander."

"Sounds like a plan. Here's APHELEIA." Theo quickly put the set of thruster rings on her neck, joints, and feet while Cassandra hit a button on her HT snail. "How hot?"

"About to boil," Yin responded. "Might need to chill."

Cassandra ran her hand through her short hair as she double-checked the hallway. "Go."

She and Theo took off through the door and towards the rendezvous point, Theo's thrusters enabling her to keep up. "Wait, where'd she go?" Theo asked.

"She has to navigate a tricky situation."

"Huh?"

"Remember who we had to fight when our battles dragged on too long?"

Theo was silent while she tried to determine what Cassandra was insinuating. "Oh that kind of navigation. So they're similar?"

"Yes." Cassandra slid to a stop behind a corner with her hand held out. Although the guards had all gone to confront Shinobu, the other employees didn't move with any sense of urgency. It was true that Yin was moving away from their current location and WoGoRPA Island was never attacked, but Cassandra would never completely understand how they could act so leisurely when danger was just a few hundred meters away.

It was impossible to be stealthy with Theo tagging along. She clenched her jaw as she focused. How dare anybody stand in her way. She was more than they ever could be. They were beneath her. Did they seriously think they could act however they wanted as if her desires weren't the most important? They were weak, and it was up to her to remind them of that fact. Theo was not among those that needed reminding. "Tenebris Lunae."

The hallway creaked under the immense pressure she now radiated. Theo looked around as they ran past the unconscious bodies carpeting the floor. "What was that?"

"Haki." She tried to limit her dominance to the hallways in front of them, but knew the chances of her drawing attention away from Shinobu increased the longer she maintained her overpowering aura.

"So you can like, do all the Haki now?"

Cassandra hummed distractedly as they approached an intersection to a hallway that led outside, then jerked to a halt so suddenly she had to restrain Theo from continuing forward. "Run to the stairs closest to the roof, doesn't matter if they're locked. Voluntas Carnae."

Even with her thrusters, Theo was hard-pressed to keep up. Cassandra tore through the building, her senses filling in whatever information she didn't remember about the floor layouts. She only stopped on the top floor, staring down each hallway in an effort to determine the best way to the roof. "That way's easier to get out," Theo provided, "but it's farther away."

"Of course it is." Cassandra headed in the opposite direction and soon came across a reinforced door.

"Okay, this leads to the wall above the testing grounds, so it's really secure. There's an eye and fingerprint scanner, a card reader, you have to insert a password…"

"Mmhmm. Armatura Nerienis." Cassandra amped herself up even more while Theo continued talking, the feeling of invincibility spreading up her arm from her fist. Theo jumped when Cassandra hit the center of the door with all her might, buckling it inward and fracturing the wall all around the doorway. Her subsequent punch sent the doorframe and reinforced section of floor and wall to which it was attached flying onto the battlement in one huge piece.

"Aren't we supposed to be escaping like we were never here?" Theo said. "You're an even worse show-off than you were before. Is Observation next?"

Cassandra climbed over the edge of the wall to hang out of sight, and Theo's boosters lessened the strain on her body as she did the same. They peeked up just enough to see the building opposite them explode apart like it had been made entirely of TNT. The huge kanabo flew through the air right after, embedding halfway in a building slightly farther away. It careened backwards just as fast as it had come, and Shinobu caught it midair as she landed several hundred meters away from them. Guards streamed after her, armed to the teeth but obviously still wary of her unusual abilities.

They waited for longer than Cassandra had expected before Yin dropped beside her and Raven crouched by Theo to give her protective headphones. "All set up. Wanna see some real pyrotechnics, kid?"

Shinobu gave a primal roar that increased painfully in volume. She threw her kanabo high into the air, her arm upheld, before bringing her hand down like she was hurling something on the ground. The kanabo plummeted like a falling star, but Yin's timing was always perfect. "Shabadabazam."

A meteorite might as well have struck the island when she snapped her fingers. Fire and debris erupted upwards exactly as the kanabo hit the ground, tremors splitting the earth apart. Even though Yin had chosen the place on the island where she could set everything up to deal the least damage to the wall and make a counter explosion to minimize the impact, the shock wave still felt like it hit them directly. Shinobu crashed through the wall, and Theo dry heaved when she saw the horrific wounds on her blue skin. The showy spectacle had made it seem like Shinobu disappeared, but it also meant she had borne the full brunt of Yin's power.

They all leaped off after her as staggered explosions shook the island. Theo's rapidly increasing anxiety as they fell was palpable, but Cassandra was anxious for a different reason. Shinobu's eyes were still closed, making it unclear if she had succumbed to her bloodrage. Cassandra really didn't want to hurt her, but she had a flashbang at the ready just in case.

Shinobu's fall slowed to the point where they could land on her, and she came to a stop several meters above the ocean. The orcas were waiting below with the boat, clicking and calling at them as Shinobu drifted over. She gradually rolled onto her side, allowing her passengers to safely dismount, and Cassandra smiled at her three green eyes. "I'm so proud of you, Shi. You did great. Thank you."

"Really, Second, that was awesome."

"Thank you for willingly adopting the form you are most uncomfortable with and risking an acute bloodrage episode, especially considering the alternate plans we could have set up."

"But it was the easiest plan." Shinobu shrunk back to her migoi form and dropped into her Sisters' arms. "Ow."

"Wait, I thought you wouldn't be hurt!" Theo exclaimed, taking in the large scars beneath Shinobu's tunic while the orcas towed them away.

"It's the mark of the oni," Shinobu wheezed. "I can only regenerate when I'm transformed. I'll turn to get rid of the rest when we're far enough away."

Theo frowned. "That seems bad."

Shinobu gave a weak smile. "I know. At least I can't die from the injuries I get while I'm an oni. I only get scars, not any of the internal organ damage, and they don't hurt that much." She glanced at her Sisters' expressions. "It's not fair to make you do the explaining all the time, Cupcake."

"Who cares about fairness?" Cassandra asked while hugging her. "You don't have to talk about it if you don't want to."

"I can't avoid it forever." Shinobu exhaled heavily and turned back to Theo. "The short story is I don't like succumbing to bloodrage and causing epidemics. My family knows how good I am - especially with the Moon Sisters' help - and I was supposed to get a Logia Fruit to cut down on me bleeding everywhere and infecting everybody. We were lied to, and I got this one instead."

"Oh. That sucks." An eyepatch bearing the crew's Jolly Roger seemed to appear in Raven's hand, and Theo lightly bounced on her feet as she put it on. "Anyway, this is HELIOS! It's a small-scale nuclear fusion reactor!"

It was hard to tell if her abrupt change in topics was her being considerate towards Shinobu's feelings or impatient to show off her invention. Shinobu eyed the cylinder warily, but Yin's jaw hit the floor. "That is a nuclear fusion generator? You're kidding, right?"

Theo looked genuinely confused at being doubted. "No. What? No! Why would I kid about that? I made one. It's right here. It's called HELIOS."

"So you're saying that you not only cracked the secret on fusion power, but you also constructed a functioning fusion reactor and made it fit inside that?" Yin asked.

"Well, I didn't do it overnight," Theo said as if that were the major sticking point. "It took me like six months to figure out fusion power, another few months to develop the reactor, and almost two years to shrink it down. I would have done it faster if I hadn't had to keep it a secret."

Yin gaped at her, then turned wordlessly to Cassandra. "I wasn't kidding when I told you she was the best applied mathematician alive before she turned eight."

"The only good thing about being there was the WG got me any material I wanted," Theo said. "I also got to talk to people all over the world to help me with different parts of it. I really got what you were saying about knowing people, Cap."

"How in the seven fucks did you make a fusion reactor?" Yin demanded.

Cassandra had really missed the light in Theo's eye when she talked about her passions. "Okay, so HELIOS is a two-part system that handles everything but refueling and disposal. The top half is the reactor itself. I made a tokamak - a toroid shell composed of polymetium - and immersed it in hypercooled nevermeltice. Once I activate it, the shell is cleared to create a vacuum. Tetratium gas is injected and ionized into a plasma, and tetratium ice pellets are also injected to control the density and manage energetic bursts that escape the magnetic field.

"Everything that isn't consumed goes to the divertor at the bottom, and helium waste is separated from the unburned fuel, which mixes with fresh tetratium and reinjected. The kinetic energy of the particles is converted directly into voltage at a rate of 21.04% - I'm trying to make it better - and the nevermeltice has to be cycled once every 220 hours or the reactor will shut down."

Everyone stared at her uncomprehendingly. "I don't know half of those words," Shinobu said at last.

Theo sighed. "Tokamak - magnetic device that confines plasma. Polymetium - custom alloy. Hypercooling - reducing a liquid over 100 degrees below its freezing point. Tetratium - the hydrogen-4 isotope that only naturally exists in outer space. Kinetic energy - the energy something has while it's moving."

"Could someone copy it?" Cassandra ventured at last.

"Sure, if they knew how to hypercool nevermeltice, knew how to make reasonably stable tetratium, and knew not only the correct ratios of metal and alloys used to smelt polymetium but also found enough of the one metal compound that only comes from meteorites, which - unlike tetratium - can't be properly synthesized. And knew the properties the alloy would need to have to prevent the shell from failing. And knew the exact steps of the smelting process. And how to even create such a metal because I designed polymetium myself."

They kept staring at her. "Are you sure you want her back?" Yin asked.

Cassandra smiled. "Will you be able to make more on our ship?"

"Yeah, but not without Alexander because the only polymetium in existence is in HELIOS and a nugget for him to learn from. What's cool is the reactor's totally safe. If the fusion fails for whatever reason, it just shuts down. The only byproducts produced are helium and a very tiny amount of nuclear waste once the irradiated nevermeltice is filtered. The SELENE support system that I need Alexander for will turn the waste into irradiated pellets - along with creating tetratium from heavy water and hypercooling the nevermeltice - which is only a little material but radiation is radiation. I have a few ideas involving Alexander or Morgan, but there's still the 'encase and dump' strategy if I can't figure anything out nine days after I activate it.

"The best way to keep HELIOS running is to completely cycle the nevermeltice every two or three days to minimize any damage to the shell. I mean, cycling after seven days means the shell will likely need to be replaced, and I literally can't do that without Alexander unless I somehow got more of the meteorite metal. I was lucky to get as much as I did, because who knows how many people have meteorite fragments without knowing what they're made of."

Yin nodded as she turned her hearing aids back on. "Are you really sure you want her back?"

"Why, do you want her?" Cassandra laughed.

"Are you kidding? She'd die the instant she joined my Family. Because I'd kill her so I wouldn't have to go through that again and again, deafness be damned."

Cassandra held Theo's head against her side and received a hug in return. "That's why she can only be my engineer; isn't that right?"

Theo giggled and rubbed her head against her captain. "The Black Glove Pirates are my home."

"You acknowledge that you have rejoined the Black Glove Pirates, which currently consist of us three," Raven droned.

"Uh… yeah, I guess."

"Then the fifth condition of your acceptance onto the crew is in effect."

"Oh, come on!" Theo exclaimed while Cassandra tried to remember which condition was which. "Really?"

Raven moved to the railing beside her. "You may not be currently undergoing puberty, but you are still a growing child. As your doctor, I am in charge of your physical health. While we cannot optimize your diet until Morgan is rescued, it is within my ability to enforce a healthy sleep schedule. It is no longer necessary for you to be awake."

Cassandra raised an eyebrow when Theo turned to her appealingly. "What are you looking at me for? The rules didn't expire just because we spent so long apart."

Theo sputtered as she tried to come up with a counterargument, then deflated and trudged belowdecks. Yin yawned and fluttered her wings as she stretched her arms above her head. "I'm out too. I nearly blasted an island in half."

"I could really use a rest," Shinobu said, scratching the burn scar on her face.

Cassandra threw an arm across Yin's shoulders and around Shinobu's back. "I'm fine, but I still think sleep is in order. You did great, you guys. I'm so grateful you're doing this for me." She paused before descending the stairs. "Of course, I'm talking about you too, Raven. Doesn't matter that you're both a Moon Sister and a Black Glove Pirate. You do so much for me, and I'm eternally thankful. Good night."

"Night, Seventh!"

"Love you, Rum Pudding."

Cassandra smiled when she heard the murmured "good night" from atop the mast.

\\'/.\\'/.\\'/.\\'/.\\

"This is total bullshit," Yin said as she watched Theo assemble NYMPHE. "I know you said she could do that, but seeing it with my own eyes?"

"Theo, what animal lays the eggs we normally use for cooking?" Cassandra asked without looking up from her annotated map of Impel Down.

"No idea," came the distracted response.

"What's a library card? How does the moon affect the ocean? How does shampoo work?" Cassandra gestured at Theo as she remained silent. "Help her out, Raven."

Raven thought for a moment. "Sebaceous glands attached to hair follicles produce sebum, a combination of lipids composed primarily of glycerides, free fatty acids, and wax esters that spreads across skin and hair. Shampoos contain organic compounds similar to sodium dodecyl sulfate."

"Sodium dodecyl sulfate is an ambiphilic organic compound," Theo said immediately, "which makes it an ideal surface active agent to bind lipid hydrocarbons to its hydrophobic hydrocarbon tail and water molecules to its hydrophilic headgroup, which means it will dissolve the sebum in water and remove it when it is rinsed out because sebum will stay on your body if you just run water over your head because, like I said, it's hydrophobic and repels water."

"That's why I hired Aisha," Cassandra explained, "to lessen that knowledge imbalance."

"Yeah, but her lessons are so boring," Theo whined. "And why does it matter if I know what a library card is or not?"

Yin tossed her a tiny wad of paper. "That's gonna blow apart when I snap my fingers. Explain that."

Theo snorted. "Do I look like Lucky Felix to you? Half the world can't be explained with life sciences and physics, and I stick to the half that can. I don't know how Shinobu's mass increases four hundred times when she transforms. All I can do is figure out how my battlesuits can deal with that. Do you really need to snap your fingers?"

"No, but it's way more awesome when I do."

Cassandra held onto her hat and walked up to the deck. "How're you doing, Shi?"

"I'd be a lot better if I could read for five minutes without being interrupted," she grumbled, focused on the book pinched between two large fingers. Her shadow seemed to vibrate on the uneven surface of the ocean due to how fast she was flying. "Yes, we're still heading in the right direction; no, I'm not getting tired; and no, I'm not going to let the boat fall off."

Cassandra grinned when she descended back into the cramped room. Yin had turned off her hearing aids again - if her complete lack of reaction to Cassandra's arrival was anything to go by - and was idly flicking cards into the tiny kitchen sink while Theo showed Raven the new caseless ammunition she had developed. Cassandra waved her hand to get Yin's attention, and all of the cards outside of the sink popped into pieces. "I got 'em all in."

"Stop being such a drama queen," Cassandra signed. "And I know drama queens better than anyone. She's a passionate kid who was just reunited with her family. Remember what Py was like when we met her?"

The card in the air burst as Yin's chuckles messed up her throw. "You mean the first time in my life I felt too bad to mute someone?"

"Of course their situations are different, but Py was also three years older than Theo is now."

"Yes, but she's a Moon Sister. Theo's just my Moon Niece."

Cassandra was unable to sign a response as she repeatedly failed to get her laughter under control. Raven relayed Yin's words to Theo, who merely frowned. "I don't get it. Why is that funny?"

Raven and Yin had a brief non-verbal exchange. "I do not understand either. While you are not biologically Cassandra's daughter, you have pretended to be multiple times and can consequently be considered the child of Yin's Sister, hence Moon Niece. It is unclear why Cassandra found this so amusing."

They waited until Cassandra straightened up and wiped the tears from her eyes. "Of course, it'd be you. You're the first non-pirate Sister to say my crew is part of your family instead of an unrelated group of people I care about a lot, even if you don't actually see it that way."

Yin didn't turn away fast enough to hide her small, proud smile. "I'm not numbering them, though."

"Just as well. Who is the second recruit and who is the third? Do you go by the one who first met me and behaves like we do or the one who asked me if they could join and behaves more as a crew member should?"

"Yin was the first Moon Sister Cassandra approached," Raven explained to Theo.

"Who was next?"

"Pythia, followed by Shinobu, Guinevere, Jordan, and me."

Yin sat bolt upright. "I was also the first to accept, no matter what the Second or Third say."

"Technically, the three of you and I became Moon Sisters at the same time," Cassandra said.

"Well, I was the first to consider myself your family, then."

Cassandra smiled. "The point is that my crew and my Sisters are equally important to me and more crucially, I don't love you separately. All of you are one big group called 'my family' that can be categorized as Moon Sisters vs Black Glove Pirates just as easily as it can human vs non-human or people taller than me vs people who are shorter. Several Sisters and pirates won't ever see each other as family, and that's okay. I'm just glad some people do."

Yin stopped mid-fist pump. "'People'?"

"Well, yeah. Excluding me and Raven, who are already family to both subgroups, did you think you were the first?"

"How am I not? Who is? Can you really claim that Lyn-"

"Lyn will at some point," Cassandra interrupted, "but she still has a ways to go."

Yin squinted into the distance as she thought, then laughed and reclined on her bed. "Yeah, you're definitely right. The Fifth said you were lucky to meet Lyn so fast, but you also got lucky meeting that bastard just as quickly. And he started as a total stranger instead of being innately connected."

Cassandra made meaningful eye contact with Raven. "My belief that Damien would kill you stemmed from him being a total stranger. He had no quantifiable incentive to grow closer to you over time, meaning he would always be willing to kill you regardless of how much time elapses. I did not appreciate the meaning he ascribed to his identity as a natural-born pirate, something that is so fundamental to his being that even he will not violate what he and Alexander consider its most basic tenets."

"Exactly. He would never kill his captain no matter how unhappy he was with them, and he won't ever violate Captain's Orders. That said, Damien has one extremely annoying habit he shares with the Moon Sisters. Intent behind orders is irrelevant. Only the exact wording matters. Isn't that right, Raven?"

"We still hate you for doing that, by the way," Yin said.

Raven stared at her. "Is that a joke? The Moon Sisters love each other, including me."

"They don't hate you; they're angry and envious," Cassandra clarified. "Besides, I would have forced anyone besides you to go back. I couldn't lose you to your family. None of us want that."