Inspired by a suggestion on Tumblr that "someone (should) write 'little Korra and Asami solve mysteries' fic."
Also, my ideas of how the characters' appearances (especially Bolin's) is inspired by masterarrowhead/dakotaa's fantastic art.
"It's gone!" Bolin screeched. He melted to the ground, clutching Pabu with both of his chubby arms and crying. The ferret squeaked in confusion and turned to face the other children, as if to ask what had upset his favorite boy.
"What?" Mako asked, a bit impatiently.
"It's GONE!" Bolin reiterated, his voice rising dramatically.
Mako controlled his exasperation enough to ask, "What's gone?"
His younger brother sniffled. "My box of animal crackers!"
Mako sighed. "I'm sure they'll turn up, Bo," he said.
"We can find them!" Korra shouted, looking up from the miniature building she and Asami were carefully constructing from wooden bricks. "Asami 'n' I are great detectives!"
Asami turned to look at the brothers, a soft grin growing on her face. "Yeah, we can look for your crackers, Bolin. Don't be sad."
"Are you sure?" Bolin asked, his eyes growing wide.
"I have my magnifying glass right here!" Korra replied, pulling it from her pocket. She quickly got to her feet, but lost her balance and fell into the building, knocking it over and splaying the blocks on the floor. She yipped in surprise.
"It's all right," Asami said, her smile by now even bigger. She rose to her own feet with an elegance unusual in a seven-year-old. "We can build it again after we find Bolin's crackers." But Korra was already past the strewn blocks, eagerly peering around the room through her magnifying glass. "Where did you see the box of crackers last, Bolin?" Asami asked.
"I ... I put them on the table when we came in," Bolin said, and he pointed to a table pressed against the far wall. Korra squealed with excitement and ran to it, pressing her glass near the table.
"There aren't any clues left behind," she said frustratedly, and her free hand began to glow with inadvertently-bent fire. "How can we solve a mystery without any clues?"
"Maybe we just have to look harder," Asami said as she came up behind Korra. "Look behind the chair. There's a piece of red paper."
"Ooh!" Korra cried. She bent down and pulled at the paper. With a quiet ripping noise, it came loose in her hand, its edge jagged from tearing away from the whole. "'Animal'!" Korra read. "It must be your box of crackers, Bolin!"
Bolin grinned. "You're a really good detective, Korra," he beamed.
"We haven't found them yet," Asami said. She took a step around Korra to pull the chair out from the table, then crawled underneath the table and plucked a box from where the chair had hidden it.
"Is it Bolin's crackers?" Korra asked excitedly.
Asami crawled back out from the table, then stood and frowned as she peered into the box. "It's empty," she said disappointedly, as she turned it upside down and shook it for emphasis.
"Ohhh!" Bolin cried shrilly, clutching Pabu even tighter and making the ferret squeak in discomfort.
"But look at what fell out!" Korra said, readying her magnifying glass and crouching to the floor.
"You spilled all the crumbs," Mako said crossly. "Now they'll have to be cleaned up."
"But maybe there are crumbs under the table, too!" Korra replied. She pressed her eye almost against the magnifying glass and bent over the floor near where Asami had pulled out the box. "I see some!" she said brightly.
"Where do they lead?" Asami asked, her face glowing with pleasure.
Her eye to her glass, Korra crawled across the room on her knees, following the path formed by the crumbs. She stopped at a small circular cushion in the corner. "It's Pabu's bed," she said, "and there's a pile of 'em here."
Bolin's eyes grew wide in confusion. "What does that mean?" he asked.
"It means Pabu took your crackers, Bo," Mako explained.
"Oh!" Bolin gasped. He held the ferret out at arm's length to look in his eyes. "How could you do that, Pabu?" he demanded in a sad voice. Pabu tilted his head and let out an "Eep!"
"He must have been hungry. Did you remember to feed him?" Mako scolded.
"Of course!" Bolin said. "I think." Mako gave him a skeptical look.
As the brothers squabbled, the girls smiled at each other. "Another mystery solved," Asami said triumphantly.
Korra grinned. "We really are the best detectives in the school!"