There was a woman watching her train. Azula spun around, catching a glimpse of light-coloured curls and an approving smile.
Then the woman pressed her finger to her lips, quiet, and vanished.
Azula stared for a moment at the place where the woman had stood. Then she blasted it with fire again and again, until the ground was scorched and no trace of the woman's footprints remained.
She didn't mention it to anyone. They would have thought she was mad.
"That's funny," said Azula. "All those years, I thought you were another hallucination."
The prisoner's smile was familiar. Her pale skin and hair were strange, but there were bruises on her arms where the guards had used force, and fine lines around her eyes. Whoever she was, the woman was human.
Even if she hadn't aged a day in nine years.
"Overshot a little," the prisoner said. She leaned forward, resting her chin on the backs her hands. It was uncouth, but she somehow made it look comfortable, even powerful. "Look at you, all grown up. Still a princess? No, right, they took the title away. Sorry."
Azula concentrated on the papers in her hands.
"According to the reports, you were caught stealing a scroll from the Fire Sages."
"I'm passionate about history?"
"My brother opened the royal archives to all."
"Yes, but I wanted the secret histories. Much more fun."
"The penalty for assaulting a Sage is branding." The woman said nothing. Azula turned the page and tried a different tack. "The machines you had with you. How do they work? What do they do?"
"You remind me of my mother."
Azula looked up. "What?"
"Harder, of course. I'd say scarier, but she'd probably just take that as a challenge. But you have a lot in common. Aside from the adolescent psychiatric dysfunction, I mean."
Azula stood up.
"Until now, you've been quite well-treated," she said quietly. "I can change that. My brother and his wife are dealing with another miscarriage, and I can assure you, by the time they're ready to look at affairs of state again, there will be no record of your existence."
"I beg your pardon?"
"That's my name." The woman traced the characters in the thin volcanic dust that covered the interrogation room. Her strokes were rough, childish, but readable: 曲水. "I was looking for Fire Lord Shijian's account of the barbarian physician who saved his life. I'm in it."
"That's a fairy tale."
"Aren't we all." River Song leaned back in her chair. "I've been threatened by worse things than you, Azula. Go and read the scroll."
Azula got to her feet and swept out, forcing herself to leave before she did something she would regret.
She wasn't surprised when the guards reported two days later that the prisoner, and her machines, had escaped. She didn't even reprimand the officers in charge. Instead, she sat at her desk and traced the same characters over and over again. 曲水.
Then she summoned the Chief Sage and had him bring her Fire Lord Shijian's scroll.
"Mom? Is it true you once killed the Avatar?"
Azula put down her brush and looked up into the innocent green eyes of her daughter.
("Being a parent's not that hard," Zuko had said. "It basically boils down to being honest with your kids, and not setting them on fire."
She was going to kill Zuko.)
"You know," said Toph, "however you answer that, you're never going to be able to discipline her again."
"Really?" Diao asked. "Is that a rule?"
"No," said Azula before Toph could make the situation worse. "It's absolutely not a rule. You have to do what I say regardless of--" She paused to find the right word, which was a mistake.
"So did you kill the Avatar?" Diao said.
"I ... thought I had very good reasons at the time."
"And he got better," Toph added.
"I had very good reasons for putting Xi Hong in a rock cage," Diao started.
Azula was saved by the entrance of a servant, closely followed by a city guard.
"This morning we arrested a woman trying to break into the palace complex," said the guard. "She insists she needs to see you. She gave us this."
He held out a scroll addressed to Bei Fong Azula. She opened it, already suspecting what she would find.
"One moment," she said.
River smiled and bowed when she entered.
"Your calligraphy has improved," said Azula.
"I brought the scroll." Azula hesitated. "Is it true? Can you really travel in time?"
River tapped the heavy leather band around her wrist. "More or less."
She opened the scroll Azula had bought, covered in Fire Lord Shijian's neat calligraphy. The paintings were particularly detailed: the blue box, the thin man with the outlandish hair, River Song herself.
"It must be very strange," said Azula, "to be able to undo the past."
"We can't do as much as you'd think," said River. "There are rules. Well, guidelines. Sometimes it's better to just live with the regret." She squeezed Azula's hand. "It gets easier. But you know that.
The airship landed with the slightest of jolts, but it was still enough to set Azula's joints to aching. She let her grand-niece lead her down the gangway. If Izumi noticed the slight tremor in her hands, she kept it to herself. Which gave her more common sense than most of her relatives. The Fire Lord, stupid boy, had attempted to forbid her from making this journey.
"The good thing about being old is that no one expects a pretence of niceness," she said.
"No one has ever expected niceness from you, Great-Aunt."
Diao waited for them at the ground, her armour polished and gleaming.
"Mother," she said, bowing. "Princess Izumi."
"Captain Bei Fong."
"You look like a ceremonial guard," Azula sniffed.
"I'm a police officer, mother. It's an honourable profession." Diao helped her into the automobile. "Are you comfortable?"
"Yes," said Azula. She caught her daughter's hand. "You look very well," she said.
Diao smiled, just a little.
"I shouldn't be doing this," she said as she navigated the streets of Zuko and Aang's city, "but I remembered your stories. It seemed the right thing to do."
There were electrical lights in the police headquarters, even in the interrogation rooms. Electricity called to Azula like lightning, but she was an old woman now, and not as strong as she had once been. But Izumi's fire was blue, and soon the Avatar would come to her for training. It was something.
"You look younger than I remembered." Azula sat down, dismissing her daughter and grand-niece. "But everyone seems young these days. Even cities, apparently."
River tilted her head.
"I don't know you. Yet."
"Pity. I was looking forward to seeing you."
"I'm looking for--"
"Yes, the scroll of Fire Lord Shijian. It's not here." Azula watched River's shoulders slump. "Tell me," she said, "why do we always meet when you're in prison?"
"Just habit, I guess." River rubbed her eyes. "What does it say about me, that I'm most at home in prisons?" She didn't wait for an answer. "You're a member of the royal family. Do you know what happened to the scroll?"
Azula leaned forward. Diao would be listening, claiming it was her civil duty rather than honest curiosity. "I gave it to you," she said softly. "Long ago."
"Good." There was a flicker of River's old-new confidence in her eyes. "Thank you."
"Do you need help getting out of here?"
"Probably not." River smiled. "I'm good at getting out of jail."
The interview was over. But Azula lingered, hesitating.
"I've outlived my wife, my brother, most of my friends. But you've been a strange sort of constant over the years. Thank you." She found a piece of paper and drew a pair of characters.
"What does it mean?" asked River.
"It's your name. Learn it." Azula got to her feet. "I don't expect I'll see you again. But good luck."
She left with all the sweeping majesty of a daughter of the royal family of the Fire Nation. Diao and her colleagues would think her an anachronism, but she didn't do it for them. The admiration in River's eyes was all the motivation she needed.
The characters for River's name are "song" + "river/water".
Shijian is "time".
Diao is "melody/song".
I do not actually speak Mandarin.