The night Astrid found the glowing squirrel, she was supposed to be asleep — tucked in tight, listening to the kind of bedtime story her grandmother always told, the perfect tales for kids ages 6-12 who lie awake wondering about the worlds beyond their windows. But Astrid had heard something scratching at the roots of the old ash tree in the yard. And there it was: a squirrel the colour of autumn fire, its tail sparking like embers, its tiny black eyes bright as two dropped stars.

"You," said the squirrel, "are not supposed to be here."

"Neither are you," said Astrid.

—

The squirrel's name was Ratatoskr, and he was the most important messenger in all the nine worlds. He ran up and down Yggdrasil — the World Tree, a giant ash whose roots dug into the land of ice and the realm of the dead, and whose topmost branches touched Asgard, where the gods lived in palaces of gold and cloud. His job was to carry messages between the great eagle who lived at the very top and the terrible dragon Níðhöggr, who gnawed at the roots far below.

"I'm going up," Ratatoskr announced, puffing out his chest. "Urgent message. No time for small children."

"I'll come with you," Astrid said.

She didn't plan to say it. Brave words sometimes escape before the scared part of you can catch them.

Ratatoskr studied her — then he breathed on her face. His breath smelled of pine sap and deep bark and something as old as mountains. And Astrid felt herself shrinking. The yard grew enormous around her. The blades of grass became tall as saplings. She shrank and shrank until she was no bigger than a pine cone. She grabbed a fistful of Ratatoskr's warm fur and held on tight.

Then he ran.

—

Yggdrasil wasn't like any tree Astrid had ever seen. Its bark was silver and rough under her fingers, but warm — warm like something breathing. The branches stretched in every direction like roads across the sky, and through the gaps between them she glimpsed whole worlds: the orange flicker of Muspelheim's endless fire, the blue-white silence of Niflheim's frozen plains, the distant honey-gold glow of Asgard far above. The wind up here smelled of lightning and cold iron and something sweet she couldn't name — and it made her eyes water and her heart feel enormous.

Ratatoskr ran in a spiral, up and up, the bark drumming under his quick feet.

Astrid, tiny as she was, could see everything clearly. Including the small scroll tucked under the squirrel's chin.

She leaned forward and read it. Níðhöggr the dragon had written:

*You are wise, old eagle, and I am weary of our quarrel. Perhaps it has gone on long enough.*

Then Astrid glanced at the scroll Ratatoskr was actually carrying to deliver.

It said: *You are foolish, old bird, and your nest is ugly. I am coming to eat it.*

Astrid's stomach dropped like a stone down a well.

"That's not what the dragon wrote," she said.

Ratatoskr's ears flattened. "Quiet."

"You *changed* it."

"I improved it."

"Improved—" Astrid couldn't finish. She took a breath and tried again. "You've been making them hate each other on purpose, haven't you? For years and years."

Ratatoskr said nothing. But his sparking tail went dim and grey.

—

They reached the top of Yggdrasil just as the great eagle spread its wings. Those wings were wider than a longship, and the wind from them hit Astrid like a wave. The eagle's eyes were gold as harvest moons, and when it looked at her, it looked all the way through her — the way only very ancient, very wise things do.

"Small child," the eagle said, in a voice like wind through mountain passes. "Why do you ride the trickster squirrel?"

This was the moment Astrid needed to be brave. Her heart hammered like a blacksmith's hammer on iron. The eagle's beak alone was longer than she was tall.

But she had read the scrolls with her own eyes.

"The message is wrong," she said. Her voice came out thinner than she hoped. So she said it again, fuller. "The message Níðhöggr sent is not what Ratatoskr is carrying. I saw them both."

The eagle turned its great golden gaze on Ratatoskr.

For a long moment, the only sound was Yggdrasil humming in the wind — a low, deep note, as if the tree itself was listening.

"Yes," Ratatoskr said at last. Quietly. "It's true."

The eagle waited.

"If they hate each other, they need me," the squirrel said, his voice smaller now than Astrid had ever heard it. "If they make peace… what am I for?"

Astrid understood then. He wasn't cruel. He was frightened — frightened of being forgotten, of mattering to no one.

She reached out and rested her tiny hand on the squirrel's nose.

"You could carry *real* messages," she said gently. "True ones. Imagine how much those would matter — carrying words that might actually end a war."

The eagle was still for a long time. Thinking. Then it dictated a reply for Ratatoskr to bring to Níðhöggr — a real one, an honest one, accepting the peace the dragon had offered.

Ratatoskr ran.

—

Astrid waited with the eagle while the night turned and the stars wheeled slowly over the nine worlds. The eagle told her how Odin had hung from Yggdrasil in darkness for nine days to earn the wisdom of the runes — not because someone gave it to him, but because he was patient enough to listen. It told her how the World Tree had survived ice ages and fire not because it was the hardest thing in all the worlds, but because its roots went deep enough.

When Ratatoskr returned, he was running differently. Lighter.

He breathed on Astrid and she grew back to her proper size — her feet in the cool grass of her own yard, the stars above her ordinary and beautiful.

"Will you carry true messages now?" she asked.

Ratatoskr looked at her for a long moment. Then his tail sparked gold again — brighter than before.

"I'll try," he said.

And he was gone, spiralling up through the dark branches of the old ash tree, up and up, carrying something real.

Astrid went inside, crept back under her blankets, and lay very still. Her grandmother slept peacefully beside her. The night was quiet. The nine worlds turned in the dark.

And somewhere high above, a squirrel ran.