Zuko doesn't understand his own bodily reactions.

DAY 8: TINY SHIVERS

Being a firebender, Zuko was used to running hot. It had saved him countless times from an icy demise at both poles, from the chill of early Earth Kingdom spring, from windy nights at the Western Air Temple. His breath of fire had even protected him inside a prison cell designed for firebenders.

It had done him wonders for getting into the good graces of the Avatar and his friends. There were only so many blankets to go around, and being the guy who didn't need a blanket went further than he ever thought it would. The deal was sealed when he began letting the younger kids use his body heat for warmth. Toph, in particular, took delight in using him to warm her feet at night.

If there was one thing Zuko could consistently rely on, it was his body heat.

So the first time Katara's hand brushed his, he was justifiably rattled.

Zuko learned very quickly, once Katara had finally forgiven him, that she was a rather touchy person. And it wasn't as if she hadn't touched him before—there had been that time in the Crystal Catacombs, and the time he'd tied her to a tree all those months ago.

Why, then, was it suddenly impossible to temper the tiny shivers that shot up his spine whenever he was the target of one of Katara's casual touches? Like clockwork—a hand on his shoulder, a shove on the arm, a skim of fingers—gooseflesh broke out across his skin, body shivering without his permission.

Even an attempt to more consciously regulate his body temperature could not counteract it. Without fail, as soon as her skin so much as grazed his, an uncontrollable shiver took hold of him.

Zuko wasn't used to being cold. Zuko was a firebender. Zuko ran hot.

Zuko was avoiding Katara.

Of course, the more he ducked around her, the more insistent her touches became. Was she testing him? Did she know? Was it just some waterbending trick? Had she not actually forgiven him?

One afternoon, she cornered him on his way back from a training session with Aang. "Zuko, you've been avoiding me."

He steeled himself. "Yes. Stop doing your weird waterbending tricks on me."

Katara's brow furrowed. "What?"

"Don't play dumb. That thing you do—every time you touch me."

A blush spread from the roots of her hair down to her neck. "Zuko, I have no idea what you're talking about."

She started to back away from him, but not before he wrapped his fingers around her wrist. "This!"

He pointed accusingly at the gooseflesh that erupted there, then at her face. But her expression had changed.

"Zuko," she said hesitantly, searching his face. "This isn't a waterbending trick. You…get shivers whenever I touch you?"

Suddenly self-conscious, he dropped his hand. "Never mind, forget I said anything." With that, he spun on his heel and started back toward the Fire Lord's beach house.

"Zuko, wait—stop walking. Come back here!" She spun him around by the shoulders, placing both of her cool hands on his face. An involuntary shudder ripped its way down his body.

"Look," she said, showing him her arm, where the fine hairs of it were raised with her own swath of gooseflesh. "Me, too."

He felt his good eye widen. And something else, too. His heart was pounding. And he wasn't cold.

"…What does that mean?"

Katara just smiled.