Two Hearts, One Processor
The Deal

{I-401} Security string confirmed. Contact TAKAO acknowledged. Data link established.

{Takao} Command: Set flagship = TAKAO

Iona readily accepted the command. It was a routine action within the Fog to designate one member of a unit as flagship. Up until her complete defeat at the hands of her sisters, that role had been Iona's for the Blue Steel "fleet" of two vessels and five mental models. Now bereft of her vessel, she was in no position to expect that would be the case any longer. Like Haruna, Kirishima, and even Hyuuga, she was now 'beached' as the humans put it.

By granting Takao flagship status over her, it permitted Takao immediate access to her log and status databases and condition monitors. Free access to those resources would shave hundreds of milliseconds off the time it would take Takao to be brought up to date as opposed to the heavy cruiser being required to query and Iona to respond to every separate record.

Zero point four seconds later Iona realized her potential blunder, but it was too late. Takao's access to Iona's logs included every detail of her time with Gunzou up until her entering standby mode as she directed her mental model's nanoparticles to complete the life support systems of the capsule she had fashioned to keep her captain safe for as long as the man could manage to stay functioning. Iona was acutely aware of Takao's particular interest in those last ten minutes before the submarine had entered standby mode, but she had no sense of Takao's motivations.

Iona already knew Takao desired Gunzou for her own. Takao had made that clear, and an inquiry with Hyuuga had confirmed the cruiser's logic. Although Iona had no ability to directly influence events now, she sequestered eighty percent of her processing resources from her flagship's access and committed it to simulations of what could be expected from Takao next.

The simulations were still inconclusive zero point five seconds later when she received another command from Takao, this time a command which engaged automatically given Iona's status now as a subordinate vessel.

{Takao} Command: Enter dialog simulation

The nothingness in which Iona had placed herself to preserve all power for life support dissolved into the familiar salon that had been established by Supreme Flagship Yamato as the default environment for mental model dialog simulations. She found herself sitting in a chair with a porcelain cup of hot tea, by the smell of it chamomile, between her hands. The cup felt hot between her fingers as steam wafted up from the rim, and oddly enough she found the sensation comforting after the cold that had surrounded her and her captain when last she had a physical body…even if that cold hadn't directly affected her.

A breeze blew past her face, rustling her long hair. The scent of honeysuckle replaced the tea in her nostrils and the sounds of bird song tickled her ears. She had to marvel at the incredible realism of the simulation. No previous dialog simulation she had participated in had anywhere near this level of detail.

From one moment to the next, she was no longer alone. Takao stood on the other side of the table, her arms crossed, looking down with a grimace.

"Takao…is Gunzou…still functional…" Iona's voice wavered and then trailed off before the taller girl could speak. Iona had hoped Takao would have reciprocated access and made Iona privy to the data being gathered by Takao, or even just the data from the capsule Iona herself had fashioned, but after one full second since contact had been made Iona was still completely blind to the world outside the confines of her processor.

Takao's grimace deepened and she turned her head to the side.

"There really is no place for me, is there…" Takao remarked softly. Iona had been introduced to the concept of a 'rhetorical remark' by the humans who were her crew, and she determined with 97% certainty that this statement was intended as such. Iona chose to remain silent. Her simulations suggested this was a critical moment, but they provided no guidance beyond that.

Despite her efforts to predict Takao's next action, she was entirely unprepared for what happened next.

{Takao} Command: Grant root access to TAKAO security string

The command was beyond the scope of Takao's role as flagship, and therefore it was up to Iona to accept or reject it. In theory Supreme Flagship Yamato had root access to all Fog vessels, but that feature had already been disabled in Iona when she had awoken in the Yokosuka docks two years ago. Iona had never since granted root to anyone, although Hyuuga's security settings came very close to it. Iona trusted Hyuuga with her life, despite the peculiar obsession the battleship now had for her. For the second time since her sinking, the concept of fear manifested within her as she examined the risks of granting root access to her new flagship.

Iona cocked her head to one size quizzically, her expression classic Fog – completely neutral. "Explain your logic for requesting root access, Takao."

Takao shrugged. "It's the only way we both get what we want."

"Want?"

"Don't toy with me, Iona!" The fisting of Takao's hands at this demand was not lost on the observant scout, even if the cruiser's face was still partially obscured. "You have Chihaya Gunzou and will not yield him. You made that clear by your actions before you entered standby. I want Chihaya Gunzou and will not yield that desire."

Takao was silent after that, so Iona provided the most likely endpoint of current events as suggested by her current simulations. "So your intention is to attempt to overwrite me, using root access to prevent Gunzou from detecting your manipulation, to change the dynamics of the situation."

Takao turned her head back and smirked to her rival. No words passed between them, but data flowed from Takao into Iona as the cruiser showed her cards. Takao was running the same simulations that Iona was performing in her sequestered space. The numbers were remarkably similar, so Iona reciprocated. The two human representations locked eyes as they compared every facet of the combined data.

One point seven seconds of objective time passed.

"So our numbers corroborate," Iona summarized within the simulation. "My data suggests an 87% chance of Gunzou detecting any manipulation on your part, with your data showing the chance being 92%. These aren't the only factors, and accounting for the others reduces your chances of success even more. You must acknowledge any course where you survive intact and I do not will result in a greater than 95% chance of a suboptimal outcome for you."

"I do," Takao responded immediately. "But I also recognise we must act quickly if Chihaya Gunzou is to survive. He needs medical care, something he cannot get nine thousand meters below the ocean surface. In the time it would take for me to return this capsule to the surface using Hyuuga's maintenance mech, he will likely cease functioning. Neither of us will accept that outcome."

Iona concurred with the assessment based on the objective data Takao was now freely sharing. She nodded, encouraging Takao to continue.

"I propose something radical. I have already begun dissolving my vessel and directing my nanoparticles to our current location…"

"That's irrational," Iona blurted, rising partway out of her chair and interrupting the taller girl. The tea cup still in Iona's hands sloshed and translucent liquid spilled onto the edge of the table between them.

"Says the one who defied her captain's orders and sacrificed herself for…love is it?" Takao raised an eyebrow and stared down Iona, who sank back into her chair. The tea cup magically refilled and the spilled tea vanished.

"Gunzou wants you as his vessel," Takao continued, her eyes narrowing as she spoke. "I don't understand it, but I acknowledge it. His…happiness…can only be ensured if you survive intact, and the only one who can make that happen…" she paused before coming to the obvious completion of her logic, "…is me."

Iona could only nod again.

"You can easily validate that we lack the facilities or knowledge to reassign all my nanoparticles to you. Hyuuga isn't here, and even if she was, there wouldn't be nearly enough time to make it happen in this environment before Chihaya Gunzou would certainly perish."

"You propose we merge," Iona provided.

Takao leaned over the table, her hands on the surface to each side supporting her. "Yes, that's exactly what I am proposing. It's the only option that will allow you to reform your vessel and get Chihaya Gunzou the care he needs in the timeframe required. If our processors are merged, the nanoparticles will become accessible to you, freely usable by default."

"Then why grant you root?" Iona challenged, taking a sip of her tea and hoping she could find an argument to maintain control of the merger she now concluded was the course of action most likely to continue Gunzou's existence. "Wouldn't it be the other way around?"

"My processor hasn't been hobbled like yours has been. I have developed a design already. Among other things, it has the advantage of uniquely keying our combined nanoparticles such that neither your sisters nor mine would be able to achieve the access you suffered with your hull. I also am used to working with my nanoparticles, so it is logical for me to perform the actions since they will form 99.7% of our new form." Takao leaned in closer to Iona, placing their faces at eye level and only a few dozen centimeters apart. "I'm ready; you're not. Any delay places Chihaya Gunzou's life in further peril. Are you willing to accept that risk, or will you provide me root access and trust that I want what is best for our captain?"

Iona spent a few moments longer running simulations and had to concur that the cruiser's logic was sound. Her proposal was the best. Still, Iona hesitated. The action Takao proposed would probably be irreversible. Even Hyuuga would likely be unable to separate the two enough to allow them to be made independent entities again. At best, they would be one processor with two cores and parallel identities, assuming Takao was even able to achieve that. At worst, they would become a single personality with unpredictable results.

But to do nothing was unacceptable.

She had already decided that Gunzou must live at any cost. Whatever their other motivations, the overarching demand for their captain's survival was something she and Takao shared. If allowing Takao to share whatever future she had with the man was the price for that survival, logic demanded she accept that price despite her unease.

{Iona} Command Accepted. Root access granted to TAKAO

***Author's Note***

This is a continuation of "He Will Live", although I chose to make it a separate story since the focus will be different. I expect two chapters. What comes next will depend on how Ep 12 of Arpeggio wraps up.

To be honest, I like the manga a lot more than the anime. I may write a story in the mangaka's source universe before my muse tires of this franchise.