Her blood sizzled on the hot coal.

'This is it. No turning back now.' Anna was beside herself with her joy.

She always knew that she could never belong in Abnegation. She couldn't be simple and selfless enough to remain in her faction of origin. She was a burst of energy that just couldn't be contained. It would've been different if her parents had still been alive. She would have chosen to stay in Abnegation for their sake. But they were gone, and they had been dead for three years now. Nothing held Anna back anymore.

Her aptitude test results pointed to Dauntless, so she chose Dauntless. She could finally get in touch with her older sister.

'For the first time in forever, I won't be alone.'

Anna would never forget her sister's Choosing Ceremony, the first time she had seen Elsa in years. Her sister's decision had completely shocked Arendelle. From Abnegation to Dauntless. Elsa, perfect and proper, with her blonde hair wrapped tight in a bun and dressed in typical drab and conservative attire. Elsa, a Dauntless? No one was supposed to publicize test results before the ceremony. But everyone felt more than certain that Elsa would be Abnegation for life. Everyone thought she would become a government official and take her father's place in serving Arendelle. Elsa proved everyone wrong, and thirteen year old Anna had resolved more than ever that she would join her sister in Dauntless.

She thought of the piercings, tattoos and tight clothing the Dauntless so often wore. She could only imagine what Elsa looked like now, how much she could've changed in the past three years.

Anna had no problem jumping out of the train, or falling into the net. In fact, she had been the first to do both. Word of the gutsy girl from Abnegation spread like wildfire. No one expected her to do this well. Even the Dauntless-born were impressed. Anna always heard horror stories about the difficulty of Dauntless initiation, but she didn't find it too much of a challenge. Not even the combat training. She learned quickly; after all, she had a great instructor.

Kristoff Bjorgman, the Dauntless initiation trainer, never held back from telling her what she did wrong. At the same time he taught her how she could improve. His blunt honesty gave away his Candor origin; he too had been a transfer.

While enduring trials of her initiation, Anna had hoped to see her sister. She only got glimpses, but the first time she saw Elsa she was absolutely stunned.

That perfect Abnegation girl was gone. Elsa seemed to have gone through a complete transformation. Tight black clothing, with hints of blue and gray, showed off curves and a slender figure Anna never knew she had. Her hair, no longer kept in a bun, was swept back like a cold flame. It ended in a single braid that cascaded down her left shoulder. Even more surprising was how much skin she showed by wearing an off-shoulder shirt. Back in Abnegation, Elsa always seemed to fully embrace the modest dress code, always wearing dresses with long sleeves and collars up to her throat. Now she sported a black wolf tattoo across her collarbone, and two more on her shoulders, both partially covered by her sleeves. Anna could see half of a snowflake on her left. And on her right...Anna wasn't sure what it was. But one thing she knew for certain: becoming a Dauntless brought out the beauty and a sense of wild freedom in Elsa.

One thing didn't change, however. Her face, though attractive, was kept blank and devoid of expression. Upon further scrutiny, Anna could tell that traces of Abnegation still remained in Elsa. She was never loud and pugnacious like the other Dauntless. She continued to carry herself with straight-backed grace and poise. Her movements were fluid yet restrained, even when she fought.

Boy, could Elsa fight. Anna had been lucky enough to sneak a peek at an intense sparring session. The crowd that had gathered concealed her from view, so Anna could see Elsa really going at it. She fought a man much bigger and taller than her, but the way she brought him to his knees seemed effortless. Elsa executed moves in rapid, almost ruthless succession, deflecting blows and lashing out with blows of her own. Anna noticed that she never grappled with him, never touched him for more than a second. Elsa brought him down to submission, but never kept her grip on her opponent.

An impressed hush fell over the crowd. Her fellow Dauntless rose with a good-natured grin and she bowed to him. Everyone burst into whoops and applause. Elsa dipped her head to the crowd next, her face serene and relaxed. Anna joined in the applause. Elsa noticed her then and her face visibly tensed, her lips narrowing to a hard line. She quickly left, never giving Anna a chance to talk.

"Elsa! Elsa!" Anna's call was lost amid the cheering. She was left hurt and bewildered.

She heard various nicknames circulating around the Dauntless compound when referring to Elsa. She-Wolf, Snow Queen...some of the more rude ones were Cold Stiff and Ice Bitch. She was better known by her most peculiar and mysterious nickname: One. But Anna would always call Elsa her sister, despite not even having the closeness of friends over the years.

Elsa became the silent yet constant presence that gave Anna strength through her initiation, even if they never spoke a word to each other.

Elsa often observed Anna's training, detached from the other trainers, arms folded across her chest and eyeing her sister with a cool, calculating gaze. Anna was doing well; Kristoff even told her he wouldn't be surprised if she was ranked number one. She expected at least some sort of acknowledgement from her sister. A compliment, some encouragement, words of wisdom, anything. But Elsa never said a word, and she turned to leave whenever Anna's turn was over. Anna tried to reach out, but Elsa would just push her away.

'Abnegation or's still the same. Why does she do this to me? What did I do to make her so distant?'

This dampened Anna's high spirits, and during lunch with Kristoff she just couldn't hold back her frustration anymore.

"I don't think Elsa's very fond of me..."

Kristoff furrowed his brow. "Who's Elsa?"

Anna gestured with her fork to the far end of the mess hall. Her older sister stood away from the tables, surveying the initiates and talking to another Dauntless instructor named Hans. They didn't seem to be on good terms, from the looks of their folded arms and tense faces. They seemed to be arguing over something.

Kristoff's eyes glinted with recognition. "Oh, you mean One?" Then he laughed. "Hans will never get over the fact she beat him in the initiation. What a sore loser. Even if he transferred from Erudite, he isn't half as smart and talented as One. I bet they're arguing over what's the best way to train initiates. Hans likes competition. One prefers teamwork."

"Teamwork, huh?" Anna said wryly. "I never would've guessed, since Elsa likes to be alone all the time."

Kristoff gave her a curious look. "If you know One's real name, you must be related to her."

Anna shrugged. "Yeah, I'm her sister."

His eyes flew wide. "Wow, that's amazing! Now that I think about it, you two have a lot in common. Except One's a lot quieter, I suppose. You'll ace the initiation for sure, just like her."

"Do you know anything about my sister?"

Kristoff shook his head. "Only that she's called One and that she's a legend. She hardly talks to anyone around here. No one knows anything. She's untouchable...literally. Maybe she has a thing for dirt or germs."

Anna sighed. "My guess is as good as yours."

He gave her an odd look. "You're her sister...shouldn't you know her well?"

She frowned as she struggled to remember bittersweet memories. "We used to be really close when we were little. All of a sudden she shut me out and wouldn't talk to me for years. It's still like that. Anyways, why is she called One?"

Kristoff held up a finger as he said in reverent awe, "One fear. That's all she has. Until she joined Dauntless, it was unheard of. The average person has ten to fifteen fears. I've seen exceptional Dauntless push to as low as four. But one?" He shook his head. "It's unreal. I remember the test like it was yesterday. One was a sensation. She totally blew Dauntless-born initiates out of the water. She pissed off Hans and really impressed the leaders, too. And to think she used to belong to Abnegation..."

Anna's curiosity exponentially increased. "What's her fear?" she asked.

He shrugged. "No one knows. In the three years I've known her...or seen her, anyway...she always acts as one of the proctors for the fear landscape simulation. Some other Dauntless would be the one to project his or her fears. She's a real mystery. If you can't get to her, I doubt anyone else can."

That made Anna feel dejected. Her shoulders slumped as she stared past her tray. Kristoff noticed this and said awkwardly, "I'm sorry. I didn't mean to hurt your feelings." He made a wry grimace. "Blame my Candor honesty."

"It's okay. Maybe you're right." Anna had grown really fond of Kristoff during her time as an initiate. She wished she had a relationship like that with Elsa, too.

A few days later Anna headed for the tattoo parlor, thinking it was about time she embraced the Dauntless look. She knew exactly what to get. To her utter surprise, Elsa was there as well. She sat still in a reclining chair, her head and neck tilted back as she got her wolf tattoo re-inked.

A young man with pierced eyebrows came out to address Anna. "What can I do for you, transfer? Tattoo or piercing?"

"Tattoo, please. I want a snowman." Then Anna faltered. "But, um... I'm not sure which shoulder..."

Anna saw surprise flash across Elsa's face. So she did remember, after all. Was she going to say something?

The young man chuckled. "Snowman, huh? Funny...One has a snowman too. On her right shoulder."

Anna made up her mind. "Put it on my left, then. Exact same design."

She was nervous about getting her tattoo done, but the pain wasn't as bad as she thought. Midway through Anna's session, Elsa had finished getting hers re-inked. She muttered thanks to the artist. But as always, she left without a word to Anna. She slipped out of the parlor before Anna even had a chance to open her mouth.

After getting her tattoo done, Anna walked away gingerly massaging her sore shoulder. She was planning on hanging out at the Pit when she saw Elsa standing alone by her usual spot. Anna stopped and backed away. She figured her sister wouldn't want her around.

"Anna, wait."

She stiffened with shock. Elsa said something. To her! She turned around to see her older sister look back questioningly.

"You're not busy, are you?"

"N-no, I have time to kill." Anna's heart fluttered wildly in her chest. "Is there something you want…?"

Elsa beckoned with her hand. "Come with me."

Anna nearly tripped over her own feet to follow her sister. She wished she could be smooth and graceful just like Elsa. Sure, Anna had the strength in combat. She had a mean right hook. But poise and balance were things she needed to work on.

Where Elsa was taking her, Anna didn't know.

"I'm sure you've heard a lot about me," Elsa said. It wasn't a boast, only a wistful remark.

Anna nodded. Suddenly she felt tongue-tied. She had so many questions to ask, and she didn't know what to say.

Finally, she asked in a small voice, "Um...c-could I call you Elsa instead of One?"

"Of course. We're sisters, after all."

Hearing that and seeing Elsa's warm smile made Anna's heart soar. Suddenly she felt more bold. More dauntless. "Elsa, why-"

"I think it's best that I show you, rather than tell you." Elsa had cut her off gently, and Anna made no objections.

"You let down your hair," the Dauntless leader remarked. "It looks good on you."

"Oh, thanks!" Anna fingered her braids and felt quite pleased. She had been inspired by Elsa's new hairstyle to change her own. She didn't know her sister could be so...nice. Was her cool demeanor just a facade? Did she have something to hide?

Elsa finally stopped. Anna's breath hitched in her throat as she realized where they were. The fear landscape. Elsa put her hand through the pocket of her pants and pulled out a pair of capped syringes.

"The program's set to enter my fear landscape. We'll go in together."

"Yours..." Anna whispered. "I can do that? Go in with you, I mean?"

"The serum connects you to the program. You'll be seeing a projection of my fear." Then Elsa gave Anna a pained look. "Do you really want to know why I'm called One?"

She proceeded to uncap the syringe and inject the serum into her neck. She did the same for Anna, who shivered when her sister's cold fingers brushed over her skin. Elsa seemed to notice this; she quickly withdrew her hands as soon as she finished.

They walked together, letting the simulation pull them in. Elsa stared ahead, and to Anna's surprise, she saw guilt and pain clear in her eyes.

"It's time I showed you the truth," Elsa said. Her voice wavered.

Anna wanted to take her sister's hand, but Elsa kept her distance, keeping her left hand tightened in a fist to her chest. Anna tried to calm her nerves as she turned to face Elsa's fear. Her one fear.

Anna heard laughter first. Then she saw two little girls running downstairs, the younger one tugging the hand of the older one.

"That's us!" Anna gasped. Elsa nodded.

The Abnegation never took photographs; until now, Anna never knew what her younger self looked like.

"Do the magic! Do the magic!" little Anna said.

And both Annas looked on with wonder as little Elsa moved her hands to conjure a ball of ice and snow.

Young Elsa and Anna proceeded to laugh and play in a room full of snow. They made a snowman together. Anna felt a rush of nostalgia and fondness at the sight. "It's Olaf!"

Elsa nodded again with a faint smile on her face.

While Anna watched with delight, she was also confused. 'This is it...? This is her one fear?'

As if she read her sister's mind, Elsa said in a tight voice: "Keep watching."

"Catch me!" young Anna exclaimed.

Young Elsa made mounds of snow for her sister to jump on. Anna watched her younger self jump higher. And higher. And higher...

"Wait! Slow down!" young Elsa cried. She slipped over ice. She fell and threw out her left hand in a desperate attempt to catch Anna. The blast of ice struck her right in the face. Anna's five year old self tumbled onto the floor, pale and unconscious.

Little Elsa sobbed as she hugged her little sister close to her. "Anna, no! You're gonna be okay...I got you..."

Anna glanced at her sister. Elsa, the legendary Dauntless leader, her role model, was close to tears herself. When Anna turned back to look, she gasped. She saw her body, stiff and frozen. She was dead.

Elsa seized her hand in a vicelike grip, startling Anna. Her heart wrenched when she heard her older sister starting to cry.

"Elsa, it's okay...I'm right here." She tried to squeeze back, though Elsa held her so tightly that she found that impossible. Anna bit her lip and endured the pain, until Elsa calmed down and convince herself that it was just a simulation.

"I-I'm sorry..." Elsa managed to say. She breathed heavily, as if they ran for miles. "I just wanted to make sure you were still with me."

Anna looked down and gasped. "You're touching my hand...I'm not hurt!"

Elsa abruptly pulled away, staring in disbelief at Anna's hand. She was right. It wasn't frozen! "How is that possible?" she murmured.

"I...I don't know. What did you think would happen?"

Elsa shut her eyes and shook her head, as if she didn't want to think about it and answer. Anna left her question unanswered. The two sisters said nothing for a while.

"So...what was that all about?" she finally asked. "You had magic powers this whole time?"

Elsa nodded. "I was born with it. We used to play in the snow all the time. Until...that." She weakly gestured to the room where her fear had been simulated. "Erudite doctors managed to save you, but our parents said that we should be separated. We did it to keep you safe…even if it meant keeping you alone and unable to remember the happy times we had. I was taught to conceal, don't feel. I had to hide my powers, no matter what. Because of that, I knew I could never be in Candor. I displayed equal aptitude in Abnegation, Erudite and Dauntless."

"And you chose Dauntless," Anna murmured.

Elsa looked away, her voice thick and tight with emotion. "I wanted to get stronger. I wanted to run be alone and free. Abnegation couldn't give me that. And I couldn't join the faction our parents hated. Dauntless was the only way out. Or so I thought..." She shook her head. "When I found out you were among the Dauntless initiates...I was terrified. I did my best to avoid you and keep my distance. Of course I want you to do well in your initiation...and I have no doubt you will. Knowing you, Anna, I should've known you would end up in this faction. You're fearless, braver than me." She made a small, wry laugh. "Everyone thought I was the perfect Abnegation girl. Completely selfless. But running away to Dauntless just proves how selfish I really am."

"Elsa, you are not selfish," Anna replied vehemently. "For the first time in forever, I finally understand. You ran away to protect me. You ran away because you didn't want to hurt me. Because you love me so much...Elsa, I can't ask for a better sister. You're smart, strong, and brave. Dauntless is very lucky to have you. I'm lucky to have you."

Elsa regarded her with wide eyes, surprised and touched by Anna's passionate statement. "You really think that?"

For a moment, Anna felt like a Candor. "Of course I do." She pulled her sister into a hug. "I love you, Elsa. Just don't push me away again, okay? You don't have to live in fear anymore. We're Dauntless sisters, we should stick together. I'll always be right here."

Elsa stiffened in her sister's arms at first. Her touch was electrifying, filling her with a warmth she never felt before. And it felt good. Love will thaw...that was the solution. Elsa returned her hug fiercely. "Thank you..."

Anna pulled back and flashed a grin. "Hey, since it's just us in this you wanna build a snowman?"

Elsa broke out into a wide smile, her eyes filled with tears of joy. The truth was out; she was finally and truly free. She could both embrace and control her power. For the first time in forever, she could finally say yes.

3/31/2014 update: I intended for this to be a oneshot, but I've received reviews and numerous PMs requesting a multi-chapter extension of this crossover. I've considered a story idea involving Kristanna (Kristoff and Anna) and Jelsa (Jack Frost and Elsa). Would you be interested in that? I'll keep this in the back of my mind, since I'm busy working on other multi-chap fics. But if enough people want it, I'll write it.

7/19/2014 update: I'm knee-deep in working on other fics, but I'll go ahead and pitch my story idea, just for you to take a look. This is the prequel/continuation I have in mind.

Title: Zero
Fandom: Divergent, Frozen
Genre: Drama, Romance
Rating: T
Characters: (Elsa, Jack,) (Anna, Kristoff,) Merida, (Hiccup, Astrid,) (Rapunzel, Eugene,) Hans
Summary: Born into Abnegation, initiated into Dauntless and gifted with Erudite intellect, Elsa is coldly determined to do away with the corruption and injustice of factions. Under the guise of Zero: the leader with no fear, Elsa rallies the Divergent and Factionless to her cause. She has the heart, the strength and the mind to succeed. But will the system prove too much even for her to abolish?