Disclaimer: I do not own Frozen; it belongs to Disney.

Anna paced back and forth outside her sister's door. To knock or not to knock?

"Oh, to hell with this." Anna rapped on the door. "Elsa?"

"Mmmhm?"

"Can I come in?"

"If you like. I don't think you'd like to be infected, though."

Anna went in anyway. Elsa was propped up against a pillow, reading a book on mathematics. Mathematics, of all things. Anna never understood the subject; who takes a perfectly fine set of numbers and twists them into countless rules and what-nots?

"Elsa, you're getting worse."

A tired smile. "Did the doctor say so?"

"No," Anna answered quickly. "He didn't tell me anything. Ok, well, he told me you were sick, you had a fever or something, and that you'll most likely... No, he didn't tell me anything." But there were tears in her eyes and she looked down.

Elsa swallowed and shifted her pillow away from Anna's sight. No need for her to see the tearstains on it. Not yet. "Anna, I've been thinking... what would you call a period of time twenty-one years long?"

"Huh?"

"I'd call it a season."

"But a season lasts a quarter of a-"

"I know, Anna, but imagine a winter lasting twenty-one years, and then spring lasting twenty-one years, and then..."

"What about it?"

"Anna," Elsa said softly. "A season always returns after it leaves. For us, it'll take eighty-four years, but winter will return. It will, trust me." She closed her eyes. "But for now, I'm almost twenty-two, and it's time for winter to leave."

"Elsa!" Anna shook her sister's shoulders. The fever must have messed with her mental faculties. "Make some sense!"

"A season lasts twenty-one years," the queen repeated.

"You mean you were only meant to live that long?"

A nod.

But Elsa's nearly twenty-two... Anna gasped. "Elsa! Were you born with it or cursed?"

One pair of tear-dried eyes met another for a moment and travelled back to their first encounter with the trolls.

"Cursed."

An icy fate, sealed with frost.

A/N: I tried to make the main idea clear, but how it's interpreted os basically up to you. Sorry if it's confusing. Thanks for reading.