6517. If any Kanmusu come into contact with Abyssal debris/flesh, and it breaks the skin, seek medical attention immediately. After what happened with Atago and Maya, we aren't taking any chances.

Yokosuka.

"Now, Takao, Choukai, I want to thank the two of you for coming."

"Thank you for having us, Dr. Mizuno." said Takao. Choukai merely stared at the wall, steadfastly ignoring the other two people in the room.

"I wanted you both here because both Atago-san and Maya-san agree that their current level of tension started roughly seven months ago, and I was hoping that all four of you could tell me what, if anything happened back then that might of set this off." said the base psychiatrist. "Before that, by all accounts, both of you got along just like any other pair of siblings."

"Well, seven months ago, Nee-san was on leave while she and Myoko got the house ready for the kids, so it was just the three of us sortieing." said Atago. "And I can't think of anything that happened on our sorties."

"Nothing really happened on the base either." added Maya. "Everything was normal, and then we just started getting angrier at each other."

"It was like night and day. One week they were fine, the next week they were at each other's throats."

"And there was nothing out of the ordinary? Nothing at all?" asked Dr. Mizuno. Takao, Atago, and Maya simply shook their heads.

"There was something." said Choukai suddenly. "Seven months ago, the three of us were on a patrol when the fleet came under attack from a trio of battleships. During the battle, one of the Ta-Classes charged the three of us while trying to get at Mutsu and Haruna. Luckily, Shimakaze managed to land a few torpedo hits and sunk her. She blew up right in our faces."

"Then what happened?"

"When we got back, I went to the docks while Atago and Maya got some bandages."

"They didn't go into the docks too?"

"We didn't need to. We didn't really get anything except some cuts and bruises, and Akashi needed the docks for Mutsu and Haruna." said Atago. "But, I don't see how that could have caused anything."

"Are you both sure nothing else happened?"

"Definitely." said Maya.

Dr. Mizuno folded her glasses. "On the off-chance that sortie had something to do with it, I'd like the two of you to go see Akashi tomorrow."

Both Atago and Maya looked at each other. "We'll do it."

The next day...

"Well, I looked up the records." said Akashi.

"And?" asked Maya.

"Aside from some cuts and bruises, the two of you were fine. So Yubari gave you some bandages to stop the bleeding while your damage control crews worked." said Akashi, reading the report. "A few hours later they gave her a glowing report that everything was normal. The only noteworthy thing at all is that that was the last time either of you were in the infirmary, aside from when Makoto, Ami, and Hotaru were born."

"Could you do us a favor?" asked Atago. "Could you scan us? Just in case something got overlooked?"

"Sure. The scanner's in my office. I'll be right back."

A few minutes later, the repair ship returned and performed the scan, plugging the information into her computer. Atago and Maya watched as Akashi's expression went from inquisitive to abject disbelief and horror.

"What is it?"

"The two of you have Abyssal tissue inside of you. How!?"

"What!?"

"I don't know how, but it's bad. Listen, I need the both of you to head into the observation room. I got to call the Yubari's on this one."

Two days later...

"Is that what was causing them to get angry all the time?" asked Choukai as she and Takao sat next to their unconscious sisters.

"From the looks of it, yes." said Akashi. "When they were wounded, bits of that Ta-class got stuck inside them, and over the next few months, slowly grew until they started affecting their emotions."

"Why didn't their crews notice it?" asked Takao.

"At first it was too small for them to notice, and once it grew, it seems to have had the same effects on them." said Akashi. "From now on, I'm gonna have any wounded stay in the docks. If no one had caught it for another few months, they'd be much worse."

"Who'd be worse?" asked Atago groggily.

"Yeah, who?" added Maya.

before anyone could say another word, Choukai broke down in sobs as she grabbed both Atago and Maya into a hug, followed by Takao. As all four girls cried, Atago felt a hand gently grip hers. She looked down and saw Maya, and in that instant, they both made one simple promise, one not to be broken by either for as long as they lived. A promise that could be summed up in one word.

Sisters.