"Yes. It's a good idea, Peter. Good luck! I'll look after the fire and then go into the wood to find the silver birch and set the string guide for Tom. Good-bye!"

David climbed down, wondering what had really happened. Either they were in for a real adventure or else the twins had been silly and spoiled the afternoon. Somehow he felt that they were being sensible.

He tidied up and put away his pad and pencil. Then he cut up a piece of turf under the tree with the scout-knife and dug a shallow hole with the trowel. Folding the secret Lone Pine document he placed it in the sardine tin, which was still rather oily. Then he put the tin in the little grave he had dug, scattered the surplus soil, and replaced the lid of turf. It was well hidden and nobody would be able to find it now.

When he had made up the fire he remembered that the kettle and bucket were still where Dickie had hidden them, so he went down the hill to fetch them. After this he decided he must hurry if he wanted to lay the trail for Tom to follow. So he took the ball of string and started up the hill to the top of the wood. He found the silver birch easily enough and tied the end of the string to the trunk and went into the gloomy wood, unwinding the ball as he went. He worked towards the edge of the wood nearest the camp and fastened the other end to the foot of a tree well hidden in the deep thicket.

By this time he could hear Sally coming up the side of the wood and Peter singing quietly to herself. He stepped out into the sunshine, and the pony's ears went back as she saw him, Peter grinned,

"Have you done it, David? You didn't surprise me. I could hear you crashing about up here half a mile away."

"Never mind me - I want to know what's happened. Where are the twins, and what's happened to Mrs. Thurston?"

Peter jumped off Sally and put one arm through her bridle. With the other hand she grasped David.

"Listen," she said, "because you'll never believe it. Mrs. Thurston is having tea with your mother, and so are the twins. I peeped in through the window. Dickie and Mary looked mad. Their faces had been washed and their hair done, and your mother was making them pass things! Oh, David! If you could have seen them!"

"I have seen them," said David grimly. "Sometimes in the hols I have to do the same myself... I wonder if they'll escape presently?... They know about Tom coming tonight, so I expect they'll be back. Did you leave the note? Did you see Tom?"

"I didn't actually see him, for I masked my face with my hankie and crept up and put the note under the knocker. I don't think he was there, but I could hear someone in the dairy... Let's go and have our tea now."