“It looks like a thunderstorm,” said Peggy, creeping up to join them.

“Oooh!” said Nora suddenly, almost squealing out loud. “Look! Someone’s coming up the hill! I can see the bracken moving! It must be one of the trippers creeping up to find us!”

The children went pale. They looked to where Nora pointed - and sure enough they could see first one frond of bracken moving, and then another and another. Someone was certainly creeping up the hill hidden under the fronds.

Nora clutched hold of Jack. “Don’t make a sound,” he whispered. “No one can possibly know we’re here. Keep quiet, Nora. We’ll slip inside the cave if he comes much nearer.”

They sat silently watching the swaying of the tall bracken as the newcomer crept through it. It was a horrid moment. Was someone going to spring out on them?

“Get inside the cave, you two girls,” whispered Jack. “I think you’ll be safe there. I’m going to slip round the hill and come up behind this person, whoever he is.”

The girls crept just inside the cave and parted the bracken that grew around it to see what Jack was going to do. He was just slipping away when the person creeping up the hillside stopped his crawling. The bracken kept still. This was worse than seeing it move! Oh dear!

Then a head popped out of the bracken, and Nora gave a loud squeal.

“Mike!” she said. "Mike!”

“Sh, you silly chump!” hissed Peggy, shaking her. “You’ll be heard by the trippers!”

Fortunately the gramophone was going loudly, so Nora’s squeal was not heard. The three children stared in delight at Mike. It was he who had been creeping up through the bracken after all! What a relief! He grinned at them and put his head down again. Once more the bracken fronds began to move slightly as Mike made his way through them up to the cave.

“Oh, Mike,” said Nora, when he came up to them. “You did give us such a fright. We thought you were a tripper coming after us!”

“I got a good view of them,” said Mike, sitting down beside the others. “There are three men and two women. They are tucking into an enormous supper.”

“Do you think they’ll explore the island as they said?” asked Peggy anxiously.

“Perhaps this thunderstorm will put them off,” said Mike, looking up at the black sky. “My word, it’s brought the bats out early! Look at them!”

Certainly the little black bats were out in their hundreds. The hot, thundery evening had brought out thousands of insects, and the bats were having a great feast, catching the flies and beetles that flew through the air.

It was the bats that sent the trippers away. One of the women caught sight of two or three bats darting round under the trees, and she gave a shriek.

“Ooh! Bats! Ooh! I can’t bear bats! I’m frightened of them. Let’s pack up and go quickly!”

“I can’t bear bats either!” squealed the other woman. “Horrid little creatures!”

“They won’t hurt you,” said a man’s voice. “Don’t be silly.”

“I can’t help it; I’m frightened of them,” said a woman. “I’m going!”

“But I wanted to explore the island,” said Eddie.

“Well, you’ll have to explore it another day,” said the woman. “Just look at the sky, too - there’s going to be a dreadful storm.”

“All right, all right,” said Eddie, in a sulky voice. “We’ll go. Fancy being frightened of a few bats!”

The children on the hillside stared at one another in delight. The trippers were really going. And no one had discovered them. Goody, goody!

“Good old bats!” whispered Jack. “Would you think anyone would be scared of those little flitter-mice, Nora?”

“Aunt Harriet was,” said Nora. “I don’t know why. I think they are dear little creatures, with their funny black wings. Anyway, I shall always feel friendly towards them now. They have saved us from being found!”

Daisy the cow mooed loudly. Jack frowned. “If only we had milked Daisy before the trippers came!” he said.

“Did you hear that?” said one of the trippers. “That was thunder in the distance!”

The four children giggled. Nora rolled over and stuffed her hands into her mouth to stop laughing loudly.

“Good old Daisy!” whispered Mike. “She’s pretending to be a thunderstorm now, to frighten them away!”

Nora gave a squeal of laughter, and Jack punched her. “Be quiet,” he said. “Do you want us to be discovered just when everything is going so nicely?”

The trippers were getting into their boat. They pushed off. The children heard the sound of oars, and peeped out. They could see the boat, far down below, being rowed out on to the lake. A big wind sprang up and ruffled the water. The boat rocked to and fro.

“Hurry!” cried a woman’s voice. “We shall get caught in the storm. Oh! Oh! There’s one of those horrid bats again! I’ll never come to this nasty island any more!”

“I jolly well hope you won’t!” said Jack, pretending to wave good-bye.

The children watched the boat being rowed down the lake. The voices of the people came more and more faintly on the breeze. The last they heard was the gramophone being played once again. Then they saw and heard no more. The trippers were gone.

“Come on,” said Jack, standing up and stretching himself. “We’ve had a very narrow escape - but, thank goodness, no one saw us or our belongings.”

“Except that footprint and a bit of string,” said Mike.

“Yes,” said Jack, thoughtfully. “I hope that man called Eddie doesn’t read anywhere about four runaway children and think we might be here because of what he heard and found. We must be prepared for that, you know. We must make some plans to prevent being found if anyone comes again to look for us.”

A distant rumble of thunder was heard. Jack turned to the others. “Not Daisy mooing this time!” he grinned. “Come on, there’s a storm coming. We’ve plenty to do. I’ll go and get Daisy, to milk her. Nora and Mike, you catch the hens and take them back to the hen-yard - and Mike, make some sort of shelter for them with a couple of sacks over sticks, or something, so that they can hide there if they are frightened. Peggy, see if you can light the fire before the rain comes.”

“Ay, ay, Captain!” shouted the children joyfully, full of delight to think they had their island to themselves once more!

There was certainly a thunderstorm coming. The sky was very black indeed, and it was getting dark. Nora and Mike caught the six hens in the little cave, bundled them gently into the sack, and raced off to the hen-yard with them. Mike stuck two or three willow sticks into the ground at one end of the hen-yard and draped the sack over them.

“There you are, henny-pennies!” said Nora. “There is a nice little shelter for you!”

Plop! Plop! Plop! Enormous drops of rain fell down and the hens gave a frightened squawk. They did not like the rain. They scuttled under the sack at once and lay there quietly, giving each other little pecks now and again.

“Well, that settles the hens,” said Mike. “I wonder how Peggy is getting on with the fire.”

Peggy was not getting on at all well. The rain was now coming down fast, and she could not get the fire going. Jack arrived with Daisy the cow and shouted to Peggy:

“Never mind about the fire! Now that the rain’s coming down so fast you won’t be able to light it. Get into Willow House, all of you, before you get too wet.”

“The girls can go,” said Mike, running to help Jack. “I’ll get the things to help you milk. My goodness - we haven’t drunk all the milk yet that Daisy gave us this morning!”

“Put it into a dish and pop it in the hen-yard,” said Jack. “Maybe the hens will like it!”

In the pouring rain Jack milked Daisy the cow. Soon all the saucepans and the kettle and bowls were full! Really, thought Jack, he simply must get that old milking-pail that the girls had told him of at their Aunt’s farm. It was such a tiring business milking a cow like this.