“Where can they be?” asked Bunker, aloud.  But there was no one on the little island to answer him.

Then the red-haired boy happened to think that perhaps Bunny might have taken the boat around to the other end of the island.  Bunker quickly ran there, but no boat was to be seen.

“They’ve either drifted away,” said Bunker, “or else they’ve rowed themselves away.  It’s too bad; but they know how to behave in a boat, that’s one good thing.  They won’t try to stand up, and so fall overboard.  I wonder if I could call to them?”

Bunker shouted, but Bunny and Sue were too far away to hear him.  Bunker then sat down on a stone.  He did not know what to do.  He looked over to the main shore, where he could just see the white tents of Camp Rest-a-While.

“Well, if we don’t come back pretty soon, Mr. Brown will know something is wrong, and he’ll get another boat and come over here,” thought Bunker.  “Then I can tell him what has happened, and we can go and look for the children.  I guess they’ll be all right.  All I can do is to wait.”

All this while Bunny and Sue were eating their lunch.  They were not frightened now, and they very much enjoyed their little umbrella-sail excursion in the boat and the picnic they were having.

But, pretty soon, it began to grow cloudy, and then it began to rain.

“I don’t like this,” said Sue.  “I want to go home, Bunny.”

Bunny, himself, would have been glad to be in camp with his father and mother, but he thought, being a boy, he must be brave, and look after his little sister, so he said: 

“Oh, I guess this rain won’t be very bad, Sue.  We’ll go back into the woods, under the trees.  Then we can keep dry.  And we’ll take the lunch, too.  There’ll be enough for supper.”

“Will we have to stay here for supper?” asked Sue.

“Maybe,” answered Bunny.  “But if we do it will be fun.  Come on!”

It was now raining hard.  Bunny carried the lunch basket, with the bottle of milk—­now half emptied—­in one hand.  The other hand clasped Sue’s.  They went back in the wood a little way, and, all at once, Bunny saw something that made him call: 

“Oh, Sue!  Here’s a good place to get in out of the rain!”

“What is it?” Sue asked.

“A cave!” cried Bunny.  “It’s a regular cave, like robbers live in!  Come on, Sue!  Now we’re all right!  Oh, this is fun!” and Bunny ran forward into the dark hole in the side of the hill—­right into the cave he ran.

CHAPTER XXIV

“WHO IS THERE?”

Sue did not run into the cave after her brother Bunny.  She stood, hugging her doll close to her, under a big, evergreen tree, so that only a few drops of rain splashed on her.

Bunny Brown, standing in the “front door” of the cave, as he called it, looked at his sister.

“Come on in, Sue!” he called.  “It’s nice here, and you can’t get wet at all.”