Maja lived in the spinning ring of Dandelion Station, where the corridors whispered if she ran on them, and the lookout windows curved like the edge of a giant bubble. Her best friend, Zipp, was a talking backpack: his zipper mouth glittered, and he could record everything he heard – the popping of oil drops, the squelching of rubber soles, and even the silence between thoughts when Maja sat listening for a long time.

One morning, the bubble mail arrived with a pop. A silver thread waved in the sphere, and when Maja touched it, the thread unraveled and hummed a melody. "The Comet Garden invites Maja and Zipp for a visit" – said the melody, as tiny light pebbles trickled inside the bubble. The invitation was sent by Tirk, a purple-leaved resident whose soft leaf-feelers vibrated instead of hair. "Need help. Our garden has gone quiet."

"A garden gone quiet?" Zipp's zipper clinked. "Gardens usually rustle. If they go quiet, that is suspicious." Maja shrugged, but was already smiling. The smell of adventure hung in the air, like the smell of freshly fried pancakes. "We're leaving."

The Bubble Walker, Maja's tiny, glass-shelled ship, was like a rolling aquarium: gently convex, transparent, and with handholds growing on all sides like grapevines. As it separated from the station's blue glowing dock, the ship sighed lightly. They pulled past a colorful fog strip where light worms wrote their names, then bypassed an asteroid carousel that floated slowly in nothingness, its pebble-sized islands dotted with swaying miniature trees. Maja put her palm on the steering wheel and felt a faint rhythm, like when two teaspoons clash in the kitchen.

"Do you hear?" she asked. Zipp recorded the sound and played it back: distant throbbing, as if space had a heart.

"That will be the rhythm of Comet Garden" – said Zipp with a serious voice. – "Or the lack thereof."

The garden didn't resemble Maja's stick-figure drawings, nor Zipp's recording collection. Dozens of ice islands, connected by ribbons, floated around a common center, like colorful balloons tied into a bunch. On every island something different grew: ice grass that rattled like a bell with every breath; stick branches that clarinetted in the wind; light foams, inside which tiny yellow fish swam, looking as if someone had blown laughter out of glass. The ribbons that held the islands together pulsed faintly. But not right now. They hung zigzagging, looking like lazy ropes.

Tirk waited for them on the rim of the nearest island, his leaves tense like ears that didn't know what to hear. "Maja! Zipp! The Windchime Heart went silent. The ribbons only hold if rhythm runs in its heart. Yesterday a dust whale flew over us and… well… sneezed."

"Sneezing is good for many things, but rarely for rhythm" – grumbled Zipp. "Where did you hide the heart?"

"Where no sharp thing fits: under the soft ice, in the Sound Passages." Tirk showed the way towards a trans-illuminating needle tunnel. The entrance opened wide as if a flower winked.

The Sound Passages were not scary, but rather weird. As they descended lower, the ice became transparent, and in its layers previous melodies ran – rustling, tinkling, and the echo of drumming rain. Zipp sometimes stopped and rewound a styrofoam hiss or willow swish; then, laughing, they slid further. Once they had to cross a wow-bridge: the ice was thin and gave out sounds like feet stepping on it. If Maja said wonderingly "wow," the bridge became longer and lighter. If Zipp hummed too loudly, the ice hardened and became stubborn.

"Asks for silence, but not muteness" – whispered Tirk, and Maja felt that this was important now, but not as a lesson, rather as a rule of a trick that would make the stunt succeed better.

Finally, they arrived at the Windchime Heart. It wasn't a real heart, but rather a system of rainbow-colored pipes and tiny bells, with a round stone in the middle whose surface shimmered with colors like light in honey. Around the stone, sticky, gold-dust-like material piled up, plugging the tiny openings of the bells. "Caramel comet tail" – puffed Tirk. – "The dust whale wanted to play with it, and its tail got stuck here."

"No need to panic" – said Maja, and knelt down. She put her ear to the stone. The cold trickled into her neck, but underneath, a dull, slow knocking sounded, as if someone were tapping two walnuts. "There was still a heartbeat. Just clogged."

Zipp leaned forward, his zipper buzzed gently. "I'll try to find the gap with sound. If it echoes back, we know where it is open." Zipp gave out three different sounds: a high whistle, a mid-low hum, and a popping rhythm, like when popcorn jumps under a lid. The whistle stayed low, the hum got stuck, the popping bounced back.

"There!" – pointed Maja, and began to circle with her finger on the pipe. "If we open this part, the rest connects by itself." Tirk quickly called the string vines; thin, silky plantlets slid out from under his leaves, and, winding, they grabbed onto the pipes as if holding a musical instrument. Maja, meanwhile, beat a rhythm: one-two, big-breath, one-two-three, tiny-knock. Zipp recorded and amplified. The rhythm shook the sticky stuff, but it still stuck, only trembling and glittering.

Then a deep, raspy sound started outside. As if a hidden cave laughed. On the wall of the Sound Passage, a huge, round shape swept past like a shadow. "The dust whale came back" – whispered Tirk. "Don't be angry at him, he was just curious. His name is Bufla."

Maja waved towards the entrance. "Bufla! Could you help? Blow, but don't sneeze! Rather hum!" The whale peeked in with one side eye and began to mumble carefully, so deep that Maja's soles were tickled by it. The mumbling permeated the ice pipes; the sticky stuff waved gently, then peeled off in tiny flakes like caramel dissolving in tea.

"Once more, just a bit faster!" – asked Zipp. Maja doubled her beat, Tirk's vines plucked gently, and Bufla picked up the melody, inserting strong, short mumblings, like salt into soup. The bells yelped at once, then got into the swing. Zipp played back the earlier thuds, the stone glowed, and the Windchime Heart came to life: tinkling, humming, whistle-skipping, and clicking rhythms swirled together, like the chorus of a favorite song the world knows.

Rising above the Comet Garden, they could see the ribbons tighten, and the individual islands approached each other gently, just enough so they could hold hands but not trample each other's ice grass. The stick branches clarinetted again, the light foams flickered, relieved, and Tirk's leaf-feelers began to dance.

"You are rescue heroes" – he said gratefully. "Will you stay for the Festival of Blooming Sounds? The bell-acorns were opening just now. If we plant one, it grows a special melody."

Maja nodded, and together they dug a hole on the soft rim of an ice island. The acorns, when they rested in their palms, were like tiny glass balls, with frilly lines inside them. Maja breathed on one, Zipp plucked a C note, and Tirk tickled it gently with his leaf-feeler. The acorn began to glow and sent a root into the ice. Usually a short plant grew above it, from which square bell cups hung. When Maja touched it, the cup giggled huskily.

"I like this" – smiled Maja. "Laughing bell." Tirk nodded. "A memory for you." He tore off a tiny rhythm pearl from next to the Windchime Heart and put it in Maja's palm. Inside the pearl, fine, barely audible pops danced. "If you spin it, you hear the garden's rhythm of today. This way you never forget the melody with which you saved it."

In the Bubble Walker, Maja put the pearl on the dashboard. Bufla blew a big, soft bubble around the ship for farewell, and on the way back, they felt as if rolling on honey. Zipp huddled on the back of the seat and nostalgically played back the first elbowing tinkling of the Windchime Heart. Maja tapped her foot to the rhythm and looked towards Dandelion Station, where she already saw the dock's light, glowing like an edible lantern.

"What should be next?" – asked Zipp dreamily. "Snow ship? Floating library? Sugar bridge?"

"The pearl will tell" – answered Maja, and spun it. The pearl made music in silence, and the Bubble Walker's nose tipped gently, barely noticeably, towards a new direction, as if it already knew where the next story waited for them. The Comet Garden buzzed behind them for a long time, like a circle of friends laughing at a well-hit joke.