At the edge of the sky, where the clouds sit thick and still as risen bread, there lived a small white unicorn named Lumi. Every evening, Lumi walked the length of her cloud and checked that the great rainbow was holding — seven bands of colour arching from her cloud all the way to the far cloud, steady and humming like a long, slow note. *Hum, hum, hum.* That was the sound of a rainbow doing its job.
But tonight, something was wrong. The middle of the rainbow had come apart. The two ends drooped away from each other, and long ribbons of colour — indigo, gold, a streak of green — had unspooled all the way down to the sheep meadow far below. Lumi leaned over the cloud's edge and looked. The sheep were standing very still, wearing the colours they had not asked for. One had a stripe of deep violet across her back. Another had gone almost entirely gold. They looked up at Lumi with their soft, puzzled eyes, their tails not wagging, their mouths not moving.
*Hum, hum, hum* — but the hum was ragged now, broken in the middle like a snapped string. Lumi stepped onto the rainbow. It was warm under her hooves, faintly springy, like packed moss after rain. She lowered her nose to the red band first and pressed it smooth — a long, steady stroke. The colour brightened. She felt it buzz faintly against the flat of her muzzle. She worked her way along. Orange, yellow, green — each one pressed back into place, each one humming a little louder as she smoothed it down. The ribbons below began to lift from the sheep's wool, curling upward like steam from warm milk, floating back toward the arc.
Then Lumi reached the gap. And sitting right in the middle of the hole — round, and grey, and rather pleased with himself — was a small cloud. He was not large. He was about the size of a lamb. He had wedged himself into the break like a cork in a bottle, and he looked, if clouds can look anything, smug. "Oh," said Lumi. "Hello," said the cloud.
Lumi sat down on the rainbow, which creaked softly. "What does it feel like," she asked, "from the inside?" The cloud was quiet for a moment. The air smelled of cold water and something faintly sweet, like the moment just before rain. "Soft," he said, at last. "Warm. Like being part of something." Lumi looked at the gap. She looked at the cloud. She looked at the gap again. Then, very carefully, she began to weave. She pressed the violet band around the left side of the little cloud, and the gold band around the right, and she tucked the green underneath him like a blanket being folded. *Hum, hum, hum.* The cloud glowed faintly grey in the middle of all that colour. A small, round button, holding everything together.
The rainbow held. Down in the meadow, the last of the borrowed colours lifted free — the gold, the violet, the green — rising slowly back into the arc. The sheep stood white again in the evening grass, blinking their long-lashed blinks, their tails beginning, at last, to wag. Lumi walked back along the arc to her own cloud. She lay down. The rainbow hummed steadily beneath her, and she could feel it all the way up through her hooves, through her knees, into her chest — *hum, hum, hum* — as the night cloud rolled in, slow and wide and dark, and covered everything gently, the way a hand covers a candle, until the world was still.
