Anne found it by tripping over it! “Oh!” she said, “here it is! I caught my foot in a bit of rusty line. Look you can hardly see it!”

“Good,” said Julian, and stepped in between the narrow pair of old, rusty lines. In some places they had rusted away, and there were gaps. In other places the heather had grown completely over the lines, and unless the children had known that they must keep straight forward, they would have lost them completely. As it was they sometimes missed them and once had to do quite a bit of scrabbling about in the heather to see if they could feel them.

It was very hot. Their packs began to feel distinctly heavy. Timmy’s biscuits began to slide round his body and eventually hung below his tummy. He didn’t like that, and George suddenly spied him sitting down trying to prise open the bag with his teeth!

She put down her own pack and adjusted Timmy’s. “If only you didn’t keep chasing rabbits, and making your pack swing about, it wouldn’t slip,” she said. “There now, it’s all right again, Tim. Walk to heel and it won’t slip any more.”

They went on and on up the railway lines. Sometimes the rails took a curve round an unexpected rock. Soon the soil began to look sandy, and the heather did not grow so thickly. It was easier to see the lines, though in some places the sand had sifted over them and hidden them.

“I really must have a rest!” said Anne, sitting down in some heather. “I feel I want to pant and hang my tongue out like Timmy!”

“I wonder how far these lines go,” said Dick. “It’s so very sandy now underfoot that I feel we must be getting near the quarry!”

They lay back in the heather and felt very sleepy. Julian yawned and sat up.

“This really won’t do!” he said. “If we fall asleep we’ll never want to start off with our heavy packs again. Stir yourselves, lazy-bones!”

They all got up again. Timmy’s biscuits had slithered round to his tummy once more, and George had to put them right again. Timmy stood quietly, panting, his tongue hanging out. He thought the biscuits were a great nuisance. It would be much easier to eat them!

The sand got deeper and soon there were big sandy patches with no heather or grass at all. The wind blew the sand up in the air, and the five found that they had to shut their eyes against it.

“I say! The lines end here!” said Julian, stopping suddenly. “Look, they’re broken, wrenched out of place, the engine couldn’t go any farther.”

“They may appear again a bit farther on,” said Dick, and went to look. But he couldn’t find any, and came back to look at the lines again.

“It’s funny,” he said. “We aren’t at any quarry yet, are we! I quite thought that the line would run right to the quarry, the trucks would fill up there, and the engine would pull them back to Milling Green. Where is the quarry? Why do the lines stop so suddenly here?”