Disclaimer: I do not own Frozen or its characters.
Anna had been stuck in the same position for several moments now. Chin on hand, lips pursed in concentration, eyes staring into the distance. Finally Kristoff had to break the silence. "Anna?" He poked her. Then again, harder, when she didn't respond. Finally, he picked up her half-eaten sandwich from the picnic blanket and dangled it in front of her eyes. "Anna?"
She blinked, coming out of her reverie. "What are you doing?"
"Wondering what's got you so lost in thought."
"Oh. Well…" She tucked a loose hair behind her ear. "I was wondering…"
"If you would drive me mad from the suspense? Because yes, you will."
She shoved him away good-naturedly. "I was wondering if you would tell me about the trolls." She clasped her fingers together nervously. "You know them better than anyone, and I was just, you know, curious. Like, how do they know what's wrong with someone, or that…certain people…you know, belong together, just by looking at them?"
"Ah." Kristoff nodded in understanding. He leaned back on the blanket, looking at the sky. "Where to begin…why don't I start by telling you the way they see things?"
"Okay." She scooted closer, and leaned forward, hands under her chin again, ready for a good story.
When trolls are at their youngest, they see the world just like you or I do. But once they are old enough, they start earning their crystals, which give them a whole new way of seeing the world. The more and bigger crystals they have, the clearer their new sight is.
They see people…like puzzle pieces.
They can see the gaps and ridges, bumps and spaces, unique to each person, that tell their life story. For example, they knew, when they first saw me, that I was an orphan and needed a home, by the gap in the family slot of my puzzle piece.
Anna grasped his hand. "I'm sorry. I know how hard it is to be alone."
"No, it's fine. Don't worry about it. Besides, I wasn't alone for long. And I always had Sven." They both smiled and he continued the story.
When they see two people, they know if they belong together by how well the edges of their puzzle pieces match up. The closer the match, the truer the love will be. It's so obvious to them that I think they forget how hard it is for ordinary humans to see it. That's why they were so…pushy, when you first met them.
He flushed at the memory. "I…hope that you…that they didn't offend you…too much."
"Don't worry it!" She reassured him. She thought for a second. "What about Elsa's ice magic? Could they see that, too? How did it look?"
Magic in a person is something that's usually shown only in the center of their puzzle piece. Most trolls can't see the centers very well, if at all. Only the oldest, like Grand Pabbie, can do that. But I've heard him say a few things over the years.
"His advice was pretty cryptic, from what I've heard," Anna said.
"Yeah, it's like I said before, they're so good at seeing a certain way, that they forget how different things are for us. He doesn't do it on purpose, but he doesn't always see all the ways that his advice can be taken. But anyway…"
Magic that comes from a curse usually starts at the outside and reaches inward. It depends on the nature of the curse how far it reaches in and covers the puzzle piece. Magic born in the person starts at the very center and pushes out. If they haven't awoken their power yet, it will stay small and hidden, sometimes even unnoticed. But once it's awoken, it reaches all the way to the edges, and becomes more visible. Usually the piece matches the color of the power. Ice magic makes a piece turn white, fire magic turns it red, and so on. The stronger the power, the more it shows up, even for the trolls with less vision.
He hesitated for a brief moment.
Elsa's magic works a little bit different from curses. When it hit you, it struck at the very heart of you, the very middle of your puzzle piece. That's why it wasn't immediately visible to most of them. That's also why it's so dangerous and can't be removed by ordinary means. It would leave a gaping hole in the middle and the person would become a shell of themselves, if they lived at all. It's not as bad if it hits elsewhere, though.
The first time I saw the trolls, back when I was very young, I saw a little girl who had been hit in the head by ice magic. It had turned part of her hair white and…
His eyes widened and he sat up straight. "That was you! How could I have never put that connection together before now?"
Anna stared at him. "Wait, what?"
"I saw you! You'd been hit in the head, and your parents were on horseback, and there was a trail of ice, and that's what I followed to get to the troll valley!" He stood and paced, unable to sit still. "That's incredible! This whole time, I never knew…"
Anna stood up, too. "Okay, Kristoff, you're rambling, and I'm not really understanding you."
He suddenly turned and swept her up in a bear hug, swinging her around. "Don't you see? Your family was the one who led me to my family!"
Sven bounded over to see what the excitement was all about, and Kristoff hugged him, too. "Did you hear that, Sven? We got our family because of Anna!" He switched to his gruff Sven voice, "That's amazing! I always knew she was special! I thought you felt that way because she gave you carrots! Well, that, too!"
Anna laughed, despite her confusion. "Okay, okay, slow down, I want to understand the story here!"
It took several moments before she understood what he was talking about. Then she was so quiet that Kristoff grew concerned. "What's wrong?"
When she finally looked up at him, tears were shining in her eyes. "Nothing. It's just that…I'm really glad that something so good came out of it."
"Oh, Anna…" Reaching out, he pulled her into tight hug. "I'm sorry, I didn't even think about what that accident cost you."
"No...it's okay…" But she clung to him anyway and let the tears fall.
After several quiet moments, she straightened and looked at him again and managed a smile. "I guess it really is destiny that we ended up together."
He smiled back. "May I?" he asked and gently kissed her tears away. "I love you, Anna."
"And I love you, Kristoff."
A/N: So, I felt like the trolls had some bizarre and random behavior, and their song kind of came out of nowhere (almost a Big-Lipped Alligator Moment), so I came up with the idea that they see people as puzzle pieces that have to be put together right away, and that it's so obvious to them, that they don't see their behavior as random or cryptic. They think that things are perfectly clear and don't know why the humans have trouble understanding what they mean!