West of the Moon by Katherine Langrish

keep warm,” said Hilde impatiently. “Keep Grandpa off the ice. And don’t worry about me. Come, Alf!” She set off, the old sheepdog trotting beside her.
    Hilde knew that long hours of tramping hills lay before her. The tough, independent little sheep roamed where they pleased and were often widely scattered. As she climbed the shoulder of Troll Fell, the wind hit her, burning her ears and forcing tears from her eyes. More ominously, the first grey flakes of snow came whizzing past.
    The sheep seemed to have disappeared. Hilde listened for the sound of bleating, or the clonking of the sheep bell worn by the old ewe who led the flock. A flurry of snow whirled down from the north-east, erasing the hillside, leaving nothing visible but a few blurred yards of wet bent grass already turning white.
    Hilde trudged on, unwilling to give up. She began to wonder if Baldur and Grim had already taken the sheep away. Perhaps there were none to find. Then it dawned on her that the sheep would shelter from the weather on the western side of the crags. She turned in that direction. Alf trotted ahead, the wind blowing up his thick fur to show the pale skin at the roots.
    A blue, unfriendly twilight descended on Troll Fell, and the snow grew deeper. Grey shapes were slinking and sliding about on the edge of sight, and Hilde remembered the trolls. And then Alf barked, once. He stood with one front paw raised, listening intently.
    â€œHave you found them?” Hilde gasped. “Good lad! Go on, then – fetch ’em down!” Alf sped away into the gloom.
    Hilde waited, stamping her feet. In a moment a couple of sheep came jogging into view. Snow was piling up on their backs, but Hilde knew they couldn’t feel it under their thick fleeces. Two more arrived at their heels – black faced and scrawny, but to Hilde a beautiful sight.
    She whistled. Alf came running, head low, snaking along behind another little group of startled, put-out looking sheep. A bell clonked dismally – he had found the old ewe. Alf looked extremely pleased with himself and grinned at her, panting.
    â€œGood lad!” Hilde did a quick head count and decided there should be some more. “Go on Alf. Seek ’em out!” Alf whisked around the sheep he had gathered, nudging them into a compact group, and dashed off into the storm.
    Hilde was smiling to see the old dog so proud of his work, when something small and solid hurled itself into her back and knocked her down. She grovelled on the wet ground, twisting and grappling. The unseen attacker let go, and she scrambled up dizzily, looking for her stick, which had spun away into the snow. Before she could find it, the creature scuttled back and gripped her around the thighs. She looked down into the enigmatic yellow eyes of a small troll, doing its best to heave her off her feet. She hammered it on the head and yelled, then stuck two fingers in her mouth and blew a piercing whistle.
    Alf came streaking downhill so fast that he overshot. His back legs slid from under him as he turned, snarling, to attack. The troll let go abruptly and melted into the darkness. Alf pursued it for a few yards, hackles up, before returning to Hilde to check that all was well.
    â€œHey,” said Hilde gently. “You brave old boy, what a good dog!” She rubbed his chest and neck. His heart was thudding against his ribs, but his eyes were bright. It was Alf ’s glory to be useful, and this was his great day.
    â€œLet’s just round up the ones we’ve got, and go.” They were near the western edge of the Stonemeadow, where the ground broke up into dangerous clefts, rocks and cliffs. It was now too dark to see where she put her feet. The best thing was to go slowly and let Alf and the sheep pick their own path.
    A gust of wind parted the whirling snow. Not too far ahead a light waved, dim and smeary, such as might come from a traveller’s lantern. Hilde’s heart