2. Euphoria

Aang was still clinging to her in shock and exhaustion, arms tightening around her legs. Her hands were streaked faint pink and black and blue, and part of her jacket was charred, along with pieces of her long hair. Her legs were sore from running, and her arms and waist throbbed from where the Autons grabbed her none too gently. But all she felt was electricity coursing through her veins, bubbling and boiling and sparking as she stood in the dimly-lit alley and stared at the man halfway inside the blue police box.

"You can come with me," he said very seriously. He didn't duck his head or backtrack with babbled apologies. He said it as if it was the most logical suggestion in the world. Katara felt no smile brighten her face, no outbreak of sweat, no hands trembling—but inwardly her heart leapt at the idea.

"This box isn't something ordinary, you know." he continued with a slight smirk. "It goes anywhere in the universe, free of charge."

Aang shuddered against her. "Don't. He's...he's an alien." She could feel his fear and disgust rolling off in waves. His jeans were singed from the fire and smelled strongly of melting, burning metallic chains and crackling, blackening wood, while his right arm bore a stinging red streak and several marks like pinpricks. Katara looked down and saw that some of his dark hair was cleanly burned away, revealing a shiny pink scalp among sweat and more cuts. "He's a thing."

"He's not invited," the man snapped, then his tone softened. "Katara, you're smart, resourceful, brave...what you did back there—"

"You'd be dead if it wasn't for me." Katara re-iterated firmly, putting her hand on her belt involuntarily, but her bag was gone.

"I would." He said it as if he'd lived died countless times, that he knew exactly how much of a threshold he could step before leaving forever. "What do you think? You could stay here, fill your life with work until it tumbles down upon you, or you could go anywhere."

Katara hesitated. She scraped the toe of her shoe on the asphalt and looked directly at him. "Is it always this dangerous? Could I die?"

He was honest. "Yes." But there was a secret pain hidden and wobbling in his throat. Who died? Who did he love? Who could he not save?

She didn't feel afraid, though. Katara felt as she did as a child while picking up another fantasy adventure book that her mother laid in her lap as a surprise. Excited. Eager. Ready to rush in, turn a new page, leave the mundane world...

She shoved it down. She had responsibilities. She had to go home, find a new job, help her father recover from Mother's death, cook more stew with her grandmother, tease her brother, go back to normal—

But she didn't want it to revert. She took another glance at her boyfriend. He certainly did. He would stumble home and fall asleep and throw himself more than ever into his daily life and pretend this—this...she couldn't put words to it—never happened. But how could she go back, knowing that there were such things as aliens and Autons and adventures and mind control and a mysterious blue box that was bigger on the inside and could travel through galaxies, worlds, space?

"No," the word tumbled out before she could rein it in. "I can't—I—I have to see my father, grandmother, go home, and...and you know."

He just looked at her, nodded, said goodbye. He didn't beg or plead, and Katara felt a mix of intense relief—he left it to me; he won't make me feel guilty—and a terrible crushing sadness as he stepped into the police box—the TARDIS—and it began to blink on and off.

Run. Go to it. It's fading away slowly, you can—

But she didn't. She stood there, legs locked by Aang's arms and something else as it began to fade in the air with every blink. And it finally disappeared. He disappeared. For good.

Oh. She stood there for a moment, letting the cold seep in. Aang was getting up, finally, taking her hand. He turned to her, about to say something, when she shook her head and stared at where the TARDIS had been—

And it appeared again and Katara was laughing and he was grinning widely with that smile. Aang was gaping in complete shock. The police box door was open, and he was still hovering in the doorway and announcing in a completely casual manner: "By the way, did I mention it also travels in time?"

Katara laughed again. He smiled again and stepped backwards.

She turned to Aang. "Thank you."

"For what?" He asked, baffled, but with dawning sorrow as he loosened his grip on her fingers, brushing the tips very lightly, still not letting go.

"For being you." She kissed him for the last time and let it linger.

Aang relinquished his grip on her, and Katara turned away from him, running, her feet entering the box with a finality that she was not afraid of.

"Can we get Sokka first?" She asked him as he closed the door behind her.

He made a face of undisguised revulsion. "Must we?"

"You'll learn to love each other," she replied as she ran her fingers over one of the levers very carefully. "Besides, I've got a lot to explain to him."

He sighed. "You're not going to make things easy, are you?"

"No."

Arms embraced her from behind, nose brushing into her hair. "Good. Now let's go get your brother, and we can take it from there. Which time period do you want to visit—past or future?"

Katara smiled and turned to face him as his arm reached around her to start the controls, the other still wrapped around her waist. "The future."

A Doctor Who AU! I recently got into the series after months of begging, and I HIGHLY recommend it. I started on the New Who series—"Rose" (1x01) is the first episode. (I'm now on "Day of the Moon")

At first, I was going to have Fanboy!Zuko, but then I started watching Doctor Who and this happened.