''I'll tell you what happened," said Dickie tersely. "That old roof has fallen in. That's what happened, and if someone doesn't come soon and dig us out we'll be jolly hungry."

Uncle laughed. "Don't you worry about that. We'll soon get out of this; but I want you both to go up to the gallery and keep a good watch from your special look-out. If you see anybody call and whistle like fun. Will you do that? I'm going back with the torch just to see if Dickie's guess is right."

And with only a little argument the twins climbed up to the platform and watched him walk across the cave till he reached the dark entrance to the gallery. Then he turned and called:

"Don't worry, kids. Chins up and keep a good look-out. I shan't be long and I'd take you along, but it's important for someone to be on guard."

"Good-bye," called Mary faintly and gulped. Then: "You'd better go up to the crow's-nest first, twin. See if there's room for me on the ledge as well."

There was room, and Dickie reached down a hand and pulled her up beside him. And there they sat facing each other in the rocky alcove, looking out over the lonely Dingle now glowing in the afternoon sun. Every few minutes they whistled and called Macbeth, but he was now far away up by the Devil's Chair with Peter. They explored their pockets and found them full of American chocolate, chewing gum and biscuits, and munched contentedly and in gratitude to Jake and Jerry.

"Better not eat it all at once, twin," said Dickie. "We may be starvin' soon if they don't find us or this Uncle man can't find a way out. We got to make it last. I hate making food last."

"I wonder what happened to Uncle Micah," Mary said inconsequently. "I like this adventure quite a bit, but I'm still 'fraid we're going to get a lot of bother from the grown-ups when we get back."

Dickie thoughtfully shifted a wad of gum to the other side of his mouth. He was thinking of what David would have to say to him. And of what his father would say, too, when he heard about this adventure, and he was not looking forward to it at all. Although not many people would have guessed it, he was tremendously proud of David, and it was not difficult to imagine how angry he would be when they did get home.

It was about half an hour later and they were getting rather frightened because Uncle had not returned, when they heard, faint and far away behind them, a voice calling.

"Hey, kids," it sounded like. "Hey, you twins. Can you come and give me a hand?"

Instantly Dickie scrambled on to the platform.

"It's Uncle. He wants us. Will you stay and look out, Mary, and I'll go and find him."