Ai carefully flipped through her forged passport for not the first time that day, feeling the weight of the paper, checking and double checking the pages for obvious flaws.

"Can you stop?" whispered Edogawa from behind a coloring and activity book that was bigger than his head. "You're being paranoid. People are going to notice you're acting weird."

Ai did not look up. "If they do, they will certainly notice that you're writing in kanji."

There was a very quiet "oh" and Edogawa fell silent and hurriedly turned to a new page.

"You two fight like an old married couple," teased Yukiko from the aisle seat. She ignored her son's protests – "Mom, stop! People can hear you!" – and chuckled to herself.

Ai limited herself to a sigh. It did not help their situation that Yukiko was a little old to be "Mom" to a seven-year-old. But she would raise a fuss if Kudou tried to call her "Grandma" or even "Aunt." At length, Ai put away her papers and instead devoted herself to the task of looking out the window as land finally came into view. They were passing over Chiba when the pilot announced that they would soon be landing in Tokyo.

She hadn't been in Japan in a couple years. It was strange to come back. She regretted not being there in the first place. She had never said goodbye, but that didn't bother her as much as it probably should have. She had never gotten to say goodbye to the people who mattered. She was used to it.

The plane touched down to the runway and skidded to a stop.

A couple hours later, they were back in Beika. For the first time in years. It seemed like forever, but of course they had only begun to taste eternity. There was still so much more in forever. The car slowed to a stop in front of the Kudou house, looking remarkably similar to how she remembered it, only older. Beyond it, of course, was the professor's house. It had not aged so well, she thought. It needed new paint, and one of the upstairs windows had been broken and covered with plywood. The windows were dark.

"Haibara?" said Edogawa hesitantly. "Are you..."

Tears were running down her face. She couldn't stop herself from crying. Kudou held her hand and she sobbed into his shirt, like she'd done only once before, a very long time ago.

She did not cry at the funeral. She did not wish to draw attention to herself. Besides, they had to wear disguises, and she was afraid that tears would mess up her makeup. Best to pretend she was a little girl who didn't understand death, who didn't understand that someone precious was gone forever. Best to pretend she didn't know the deceased at all, and had just been dragged here by the Kudou family.

She did not cling to Kudou, either. He had his own grief to work through, and it was different from her own. He had known the professor since he really was a child. He had two living parents. He still had so much left to lose.

The two of them spent the next day revisiting old haunts. Teitan Elementary, "haunted houses" they had explored with the kids; they even walked past the Mouri Detective Agency, despite Edogawa's reluctance to be anywhere near the place. It was apparently still in business, although Poirot was gone, replaced with some other restaurant. They went to a run-down old ramen shop nearby, which seemed to put Kudou more at ease. Thankfully, the owner believed their excuse about their parents shopping next door and served them with no concerned interrogation. They did get a few worried looks from other patrons, so they hid themselves in a booth in the corner of the restaurant.

"I'd like to stay in Japan," she told Kudou as they ate. "International travel is a pain."

He agreed. Neither of them mentioned that fake passports would probably be much harder to come by in twenty years. They wouldn't have Yukiko and Yusaku's connections forever.

"We'll have to bring over all of my equipment, of course," she said. She had a full lab set up at the Kudou's place in Los Angeles.

"Haibara," said Kudou softly. "Is a permanent antidote even possible?"

She finished chewing on a bamboo shoot. "We will not know until it is done," she admitted. "Are you giving up? Perhaps it is already possible for us to live comfortably as recluses, using the temporary antidotes when absolutely necessary. But I doubt you would take to that lifestyle."

Edogawa's tiny hands clenched into fists. He said nothing.

"I was a fool working with concepts beyond my understanding when I made APTX," she said. "But our condition is mine to repair. I will not give up on this, so you aren't allowed to, either."

"Not that I don't want to stay in Japan, but how are we going to live here?" he asked. "Before now it might have been a possibility, but..."

"We'll do things ourselves," said Ai. "We are fully capable of that."

"My parents won't believe that," sighed Kudou.

Ai gave him a skeptical look. "They thought you could take care of yourself at fourteen, why not at thirty-seven?"

Kudou shushed her, looking fearfully around the restaurant at the other diners, who were all far too engrossed in their own conversations to hear a word said by the two children in the corner.

"We'll be fine," said Ai, more to herself than anything. To Kudou, she said, "I have a good feeling about the most recent prototype. It might not be that much longer. And then we can get on with our lives, go anywhere we want. I just don't want to be stuck in LA in the meantime."

"Right," said Kudou. He could tell that she was over-promising, she knew that, but she also knew that she had said exactly what he needed to hear.

They paid for their food and walked back. Ai wanted to get a sense for what needed to be done. She didn't trust Kudou's parents to go through the professor's things, and had asked that they not touch anything without her. They had never lived there – it was not their home. This was her responsibility.

They turned onto their street. Ai's gaze drifted to the front gate of the Kudou residence. She must have looked awful that night, passed out on the sidewalk, drenched from the rain, and draped in clothes that didn't fit her. Perhaps any decent person would have helped, but Ai did not believe most people had great reserves of decency. And even after realizing who she was and what she had done, the professor had still let her stay with him. Kudou had yelled at her and blamed her, and rightly so, but Agasa had always assumed the best and forgiven the worst. She doubted she would ever meet someone so kind. She supposed he had been like a father, but she wasn't really sure what fathers were supposed to be like. She'd barely known her father, and she did not think that Kudou's parents were at all typical.

"...Haibara?"

She had stopped in front of the professor's house.

"You can wait next door if you don't want to come," she told him. "I'll be there in a few minutes." He nodded and kept walking.

She still had a key to the house. The professor had left the door unlocked usually, but once she started living there, it was always locked. Not that a locked door would have stopped Them, but it had given her peace of mind. She'd gotten a second chance, here, and however difficult her life or her research might be, she would always be grateful for that. She opened the door and slipped off her shoes.

"I'm home," she whispered to the quiet house.

At the edge of her memory, she could almost hear someone say, "Welcome back."