Aliens In The Family by Margaret Mahy

when he talked to his teacher. "But Bond must realize that broken rules have direct results. The circumstances have become most interesting. We forbid excessive interaction with the inhabitants and yet our richest learning takes place when such interaction is involved.
    "I did not expect such innovation," commented the winged Galgonquan. He turned to the comatose figure. "Solita. What is the present situation?"
    "Speed and distance," Solita replied without opening her eyes. "The coordinates alter continuously. The Wirdegen would have lost contact had they not recruited a spy."
    "The pursuers will have to make a jump if they are shaken off," the teacher observed. "That could be critical. See how a small deviation such as accepting help willingly offered, can lead to other more difficult modifications?"
    "Pinpoint the coordinates when possible," the winged figure commanded Solita. "Is there any reference or name that we can check on?"
    "Rackham Rides," Solita said immediately. "And Webster's Valley," she added after a pause.
    "Ah, yes. We have collected other students there. That may be why the inhabitants believe it to be haunted. There have been some unfortunate instances in the past."
    On the bed Solita stirred, and when her lips moved a voice issued that was not her own. "Not Webster's Valley! Everyone knows it's haunted. The trees change places," said Dora's voice in the school beyond the moon.

    "The trees change places," said Koro in 1838.
    "It's the shortest route," Sebastian Webster said. He barely noticed the stone tug at his ear.
    They walked along a wooded ridge surrounded by the dark, rich smell of the live, green leaves and the thick, damp mulch piled up under banks of fern and moss. An unseen creek made a faint, melancholy sound below them, and a little native fantail perched pertly on a branch above their heads, chirped cheekily as it danced a little on the twig, then swooped down so low they could have touched it.
    "Tenaa, Wehipa" said Hakiaha. "You tell me—how can one man think he owns all the land?" He was thinking of the landowner and the farm they had left behind them.
    "I'm not like that myself," countered Sebastian, very aware of his fair hair and blue eyes. "I used to be a sailor. I don't put up any fences."
    But Hakiaha looked at him doubtfully, and Sebastian Webster felt the division between them as a distinct chilliness—all the more because he knew that even if he did not erect fences other white men would, and he was frightened that he might find himself on one side of the fence, with Koro and Hakiaha on the other.

Eleven - A Valley of Ghosts
    At first the horses moved in single file, zigzagging backwards and forwards along a track which looked like a thin thread cobbling the cleft hillside together. Divided by a gully of dense native bush, the hill looked as if it had once been struck by the wand of a powerful magician and had never recovered from the blow. The riders were surrounded by trees and ferns. Unexpected clearings showed ranks of trees climbing up and down the slopes, uneven drifts of their own fallen leaves spread across their twisted, mossy toes. The path ahead was wide enough for a horse to travel comfortably as the low branches had been trimmed back, but the bright, sharp sunlight of the world beyond the living canopy became softer by the time it reached the forest floor.
    Not very far behind them were the paved yards of Rackham Rides, the office with its filing cabinets, the Range Rover and all the things that clearly proved that humankind controlled the world. And further beyond was the city, and in the city the new house which now seemed like a memory of long ago, though they had left it only that morning. The bush closed densely around them as if it must stretch out for miles, and it was easy to believe that they had passed into a world with no other people but themselves.
    Philippa sat astride a solid, black gelding called Blackberry, who would sometimes kick out if he sensed