“The tower rooms have been furnished,” he said. “I found that out from one of the women who is cleaning the place. So they are going to use the tower.”

“Yes - they are going to use the tower!” said Mike, looking at the others. But they did not tell George what they knew. He was very nice - but he was almost grownup and he might think, perhaps, they should tell Miss Dimity - and they did so want to follow the adventure themselves and find out everything before any grown-ups came into it.

That night the children undressed in great excitement. Jack was to take the first watch, from ten o’clock to twelve o’clock. Then Mike was to watch from twelve to two and Nora from two to four. By that time it would be daylight and there would be no need to watch.

The next night Peggy was to begin the watch. “We must sit by this window, and keep our eyes on the tower of the Old House,” said Jack. “If any of us sees a light flashing or burning there, he must wake the others at once - and then we’ll all creep down to the beach, hide in a cave and see if we can spot the boat coming in.”

Peggy and Nora went down to their bedroom. They found it difficult to go to sleep. Mike got into bed and talked to Jack, but they both fell asleep very soon. Jack had set the alarm clock to wake him at ten.

“R-r-r-r-r-r-ring!” It went off shrilly at ten o’clock. Jack sat up and switched it off. “Good thing Dimmy gave us our rooms right away in this tower,” he thought to himself. “She would be waked too, if we slept anywhere near her. Mike, are you awake? Well, go to sleep again. I’m going to watch now, and I’ll wake you at twelve.”

Jack put on a dressing-gown, and sat down by the window that looked towards the tower of the Old House. It was a dark, cloudy night. Jack could not make out the tower, stare as he might.

“Well, I should see it if it had a light in it,” he thought.

An owl hooted in a distant wood. A moth fluttered in a corner near Jack’s head and made him jump. He yawned. After the first five minutes, it was rather boring to sit and look at dark nothingness.

He was glad when it was time to wake Mike. Mike stumbled sleepily out of bed, dragged on his dressing-gown, and went to sit by the window. Jack tumbled into bed thankfully and was asleep in a second.

Mike sat and stared sleepily at the tower of the Old House. He could just see it now, for the sky had cleared. The tower was dark. Mike felt his eyes closing and he jerked his head up. He got up to walk about, afraid that he might fall asleep in the chair.

When his two hours were almost up, he heard a sound in the bedroom. And a hand touched his shoulder. Mike almost jumped out of his skin. He hit out and struck something soft.

“Oh!” said Nora’s voice. “You hurt me, Mike! I’ve just come up to tell you it’s my turn to watch.”

“Well, what do you want to come creeping in like that for, and make me jump!” said Mike crossly. “I thought you were a smuggler or something!”

Nora giggled and took her seat by the window. “Get into bed,” she said. “It’s my turn now. Oooh, I do feel important!”

That night nothing happened - neither did anything happen the next night or the next - but on the fourth night there was great excitement. A light flashed in the tower at midnight! There it was, as plain as could be!

It was Peggy who first saw the light flashing in the tower of the Old House. Mike had had the first watch that night, and Peggy had come up from her room about one minute before midnight to take her turn at watching.

She whispered a few words to Mike, and took her seat by the window.

“There hasn’t been a sign of anything,” Mike said in a low voice, and he threw off his dressing-gown to get into bed. “This is the fourth night we’ve watched - it’s a bit boring, I think. Do you suppose that...”

But just at that moment Peggy gave such a loud squeal that Mike jumped. “Mike! Oooh, look! Mike! There’s a light in the tower. It’s just come, this very moment!”

Mike ran to the window, almost falling over a chair on the way. Jack awoke at the noise.

“Yes!” said Mike. “It’s a light! Jack! Jack! Come and look!”

Jack jumped out of bed and ran to the window. Sure enough, there was a light in the distant tower - a light that dipped and flashed and dipped and flashed.

“They are signalling,” said Jack, in excitement. “The boat must be standing out to sea watching for the signal right beyond that rocky crag we sailed round.”

“Shall we get on our things and slip down to the beach?” said Mike so excited that he could hardly stand still.

“Yes,” said Jack. “Peggy, wake Nora. There’s no hurry, because if that light has only just shone out of the tower, it will take some time for the boat to get round to Spiggy Holes. We’ve plenty of time to dress properly.”

Peggy flew down the winding staircase to tell Nora, who was still sleeping soundly. Peggy shook her, and Nora woke up in a hurry.

“Nora! The light’s in the tower! Hurry and get dressed, because we’re all going to creep down to the beach and hide in a cave to watch,” cried Peggy. Nora almost fell out of bed in her excitement. They put on their clothes in the dark, for Jack had forbidden lights of any sort in their tower, in case they should be seen from the Old House.

“If we can see their light, they could see ours,” said Jack.

“True, Captain!” said Mike and dressed himself at top speed. He put on both his stockings inside out, and buttoned his coat up wrong - but who minded?

They were all ready in five minutes. Jack took his torch and gave one to Peggy for the girls. They all crept down the staircase, out of the little tower door, and down the garden path, where the smell of honeysuckle came to them.

“Nora’s got on her bedroom slippers,” said Peggy, with a giggle. “She couldn’t find her others.”

“Sh!” said Jack sharply. “Other people may be about, remember. We mustn’t be seen or heard.”

They went as quietly as they could down the rocky path to the beach. The tide was half in and half out. The moon swam out from behind a cloud and lighted up the shore for the children. Jack stopped and looked out over the sea.

“No sign of any boat yet.” he whispered. “Let’s get into one of the nearest caves and get settled before anyone arrives. I expect the people from the Old House will come down to the beach soon.”

The children went into a small cave not far from the steep cliff path. They thought that if they hid there they could easily see who came or went up the cliff. They sat on the dry sand on the floor of the cave and waited, speaking in whispers. Nora was shaking with excitement. She said her knees wouldn’t keep still.

Suddenly the children heard voices, and they stiffened in surprise. The voices were to the right of them. Jack cautiously peeped out of the cave when the moon went behind a cloud.

“I believe it’s the man called Felipe Diaz and that sleepy-looking chap called Luiz,” whispered Jack.

“But, Jack, how in the world did they get on to the beach?” whispered back Mike. “We didn’t see them come down the cliff-path - and that’s the only way down on to the beach for a couple of miles! The cliffs are much too steep anywhere else to get down to the shore.”

“That’s funny,” said Jack. “They couldn’t have been here already, surely, or we’d have seen them. Perhaps they were waiting in a cave. Good gracious, I hope they didn’t spot us!”

Nora went hot and cold when she heard Jack say that. Mike shook his head.

“If they’d seen us they’d have rushed us off the beach at once,” he said. “They wouldn’t want us to see what was happening to-night. Listen! What’s that!”

The children listened - and over the black and silver water they heard the sound of a low humming.

“It’s a motor-boat!” said Jack, in an excited whisper. “It’s been waiting out yonder, round the crag, for the signal. Now it’s coming in! Watch out, everyone. See all you can.”