So Peter raised her head carefully, and after a quick glance round, beckoned David up and pointed. The stranger was about two hundred yards away now and had paused to light his pipe. Then he seemed to consult either the map or the paper again before easing the knapsack on his back and starting off at a smart pace along the track to the north.

Peter led them well. There was no cover but the heather, and although occasionally they were able to walk or trot upright, they spent most of the time on their stomachs. But the stranger only turned round once and it was obvious that he was unaware of the four Indians on his trail and the fearful fate which awaited him if he was caught.

After some minutes of strenuous trailing, Peter waited for David to come up with her.

"We'll soon know where he's going," she said. "There's a track to the left, leading down the other side of the mountain. If he takes that it will take him to Appledore - a farmhouse rather like Witchend. If he goes on, he'll either have to turn down one of the gutters like ours, or walk along the top of the Mynd for another six miles... I wonder who he is, David?... How are the twins getting on? Not too tired?"

'"Course we're not tired," said Mary indignantly.

The man was walking fairly fast, but as it was easy to keep him in sight Peter did not rush them. Once, when he seemed to pause, they fell flat in the heather and David heard the twins muttering behind him.

"Get down," snapped Peter.

"I won't," squeaked Mary "I won't. There's a snake - a beastly, horrible black squiggly snake."

"It didn't bite you did it, Mary? You're quite sure it didn't? Did you see if it had a white V on its head? Was it an adder?"

Mary looked bewildered and frightened, so Richard answered for her. "No," he said stoutly. "No, we haven't been bitten, thank you, but we've been in great danger. No - it wasn't an adder. It was a cobra or... or a bostricter! 'Bout twelve feet long it was."

"Well, whatever it was," said Peter, "we'd better get out of the heather and onto the path. It may have been an adder. There are lots up here."

Peter suddenly looked rather crestfallen. "I'm afraid we've missed him now," she said. "He's just disappeared so he's probably gone down to Appledore on the other side. There are no gutters on the west side of the mountain and it's a steep climb down."

"What's Appledore?" said Mary.

"I was telling David. It's a house rather like Witchend. A lovely place but very lonely and with a big wood round it. About six months ago a Mrs. Thurston took it. I've never seen her."