Zuko stuck a flag into the top of the castle as Mai set their toddler's feet onto the sand.

"Did she make it in time?" Zuko asked.

"Yes," Mai said. "Finally, no more diapers. Yay."

Their daughter threw her arms up. "Yay!"

"I'm so proud of you." Zuko couldn't stop himself from beaming. "Look, I made you a castle. Do you like it?"

The princess snatched her hand out of her mother's and inspected the castle. "People is inside?" she asked, her head tilting sideways.

"Pretend people, sure," Zuko said. "Maybe there are some pretend servants inside."

Her tiny foot kicked over the castle. "All dead now!" she announced.

"Why would you do that?" Zuko demanded. "You can't kill your servants!"

"Yes, all dead!" She clapped her chubby fingers together and gave a shriek of laughter that seemed too sinister for a two-year-old.

"That's not funny!" Zuko said, his temper rising. "We don't kill people unless we absolutely have to, and when that happens we definitely don't laugh about it!"

"Calm down, Zuko." Mai rolled her eyes. "She's just playing."

"Calm down, Zuzu!" the princess echoed, her tongue tripping over her father's name.

Mai covered her mouth and snorted with laughter.

"It's not funny!" Zuko stood up, his stomach churning at the nickname. "Stop encouraging her! I don't want her to turn out like... like that."

"Turn out like what?" Mai asked. "Like your dad?"

"Like my crazy sister!"

Mai sighed. "You're overreacting. She's not going to turn out like that. And Azula seems to get less crazy by the day, anyways."

The princess's face brightened at the name. "We see Aun' 'Zuwa?"

"Maybe later," Mai said. "We're still playing at the beach right now."

"I'm going home," Zuko muttered, pulling a robe on. "You two can stay if you want."

The palace was quiet when Zuko arrived. Azula sat at her desk, a piece of parchment and a bottle of ink in front of her. She was biting the end of her paintbrush between her lips. Predictably, Ty Lee sat next to her on the little bench. They both wore their full armor, green and gold snuggled against red and black, but Azula's hair was down and Ty Lee's face had been scrubbed of makeup. Zuko cringed. Informal conversations got so much more awkward when Ty Lee was around.

"Uh, hi," Zuko said, alerting them his presence. "I need to talk to Azula. About family stuff. So, uh, bye, Ty Lee."

"You have the worst manners, Zuzu," Azula chided. "Ty Lee is family."

"It's okay," Ty Lee said brightly. "He's getting a lot better. Remember when he used to just say 'out!' until I left?"

"True," Azula conceded. "Do you mind terribly?"

"Nope!" Ty Lee kissed Azula's cheek. "I'm going to find a snack. Have a good talk!"

She leapt up and glided out of the room. Zuko shut the door behind her and then stole her spot on the bench.

"Do you mind sitting in the other chair?" Azula asked. "Dr. Yakhoa thinks we need to 'start developing more appropriate physical boundaries.' And she said you need to start knocking before you barge into my bedroom."

Zuko moved to the other chair without comment. Dr. Yakhoa had worked some near-miracles on his sister; if the healer said Zuko needed to respect Azula's boundaries better, he couldn't afford to argue.

"So, what brings you here?" Azula asked, wiping her brush on a rag.

"I need to know what would have kept you from turning evil," Zuko said.

"The past is history," Azula said. Her tone didn't change, but her muscles tensed just enough that an acquaintance wouldn't have noticed it. "There's no use in trying to change it."

"I'm trying to change the future," Zuko said. "Your niece is as bloodthirsty and power hungry as you used to be."

"I was never inherently bloodthirsty or power hungry," Azula said. "I'm a perfectionist, and I needed to be the best at whatever was most important to Father. That just happened to be war."

"She has your laugh," Zuko persisted. "She knocked over a sand castle and laughed that everyone was dead. Tell me how to stop her from taking over the world and having a nervous breakdown before she finishes puberty!"

Azula shrugged. "It's really not that complicated. Don't neglect her, don't abuse her, and don't put her under an unreasonable amout of pressure to succeed."

"It's really that easy?"

"I never said it was easy," Azula said. "Or maybe it just wasn't easy for our father. But it is simple."

Zuko played with Ty Lee's metal fan. "Do you ever wonder how you would have turned out if Mom hadn't left?"

"The past is history," Azula repeated like a mantra. "But I do think about it sometimes, even though I'm supposed to be concentrating on the present, and I think I would probably still be trying in vain to please Father. I'm glad that I went mad and utterly failed at everything he expected. It was a lot easier to figure out what I actually wanted when no one expected me to do anything but scream at mirrors." She picked up the rightmost of two steaming teacups and sipped it. "Isn't that what you always say? That you're glad Father banished you?"

Zuko nodded.

"It was exhausting to always be perfect," Azula said. "And I was meant to rule over soldiers and battle strategies, not commoners and taxes and dull moral dilemmas. If Father hadn't pushed me to be like him, perhaps I would have turned out differently."

"I just want her to be happy and safe," Zuko said. "I want her to grow up and be a good person."

"Then the princess should be fine," Azula said, turning back to her letter. "Tell her all of that. Tell her that you love her, even if she decides to fall in love with a circus performer and abdicate her title and play soldier in the woods every day."

"I will," Zuko said. He stood up, but paused at the door. "Azula, I know you don't like kids, but if something happened to me and Mai and Uncle and everyone else, would you-"

"I know what it's like to be abandoned," Azula said coolly. "My entire family abandoned me, and none of them even had the excuse of being dead. I would never do that to my own niece. And I wouldn't let her take over the world, either, if only because that kind of conquest won't be fiscally possible for another fifty-two years."

Zuko's shoulders sagged in relief. "Thank you. For everything."

"It's nothing." She waved him away. "I have armies to command, Zuzu. If you see Ty Lee, would you be so kind as to send her back?"

Zuko found Ty Lee in the kitchen, babbling away at Mai with a half-eaten apple in one hand. Mai rocked in the padded wicker chair, patting the bump under the nursing blanket she'd draped over her shoulder.

"Azula wants you," Zuko said to Ty Lee. "Sorry for kicking you out earlier."

"It's okay," Ty Lee said, hopping off her stool. "It is your palace. See you later, Mai!"

Mai waved at her best friend. "Feeling any better?" she asked Zuko.

"Yeah." Zuko kissed the top of her head. "Lots better. I'm sorry for leaving."

The blanket fell off Mai's shoulder, revealing a nursing princess with the red cloth bunched up in her fist. She broke away from the nipple and smiled at him. "Daddy," she cooed, milk dribbling down her cheek.

"Hi there," Zuko said, tapping her nose. "Finish your supper."

"All finished." She stretched her arms up towards him. "Carry me, Daddy."

Zuko hefted his daughter into his arms, and she rested her ear against his shoulder. "I'm sorry for yelling at you," he said, stroking her hair. "I love you forever, no matter how many sand castles you kick."

She hugged his neck and yawned into his ear. "Okay, Daddy."

Mai gave her husband an approving look as she buttoned her blouse up.