“Look, you can just see it, straight over where the gypsy camp is!”

Dick managed to pick it out. “It’s very small,” he said. “Smaller even than I thought it was last night. Look, it’s coming down!”

But it wasn’t. It merely swept low, and then went round in a circle, as it had done the night before. It rose a little again and then came in low once more, almost over the boys’ heads.

Then something extraordinary happened. Something fell not far from Julian, something that bounced and then came to rest! It made a thud as it fell, and all four jumped. Timmy gave a startled whine.

Thud! Something else fell. Thud, thud, thud! Anne gave a squeal. “Are they trying to bomb us or something. Julian, what are they doing?”

Thud! Thud! Julian ducked at the last two thuds, they sounded so near. He took hold of Anne and pulled her down into the quarry, calling to Dick and George.

“Get down here, quickly! Force yourselves into the caves somewhere! We shall get hit!”

They ran across the quarry as the plane swooped round in a circle once more and then again began dropping the things that went thud! thud! Some even fell into the quarry this time. Timmy got the shock of his life when one bounced in front of his nose and rolled away. He yelped and tore after George.

Soon they were all safely squeezed into the little caves that lined the sides of the quarry. The plane swept round once more, up and then round, and the thud-thudding began again. The four could hear that some of the thuds were actually in the quarry again and they were thankful they were well sheltered.

“Well, nothing is exploding,” said Dick, thankfully. “But what on earth is the plane dropping? And why? This is a most peculiar adventure to have.”

“It’s probably a dream,” said Julian, and laughed. “No, not even a dream could be so mad. Here we are, snuggling into sandy caves in a quarry on Mystery Moor, while a plane drops something all round us in the middle of the night! Quite mad.”

“I believe the plane’s going away now,” said Dick. “It’s circled round but hasn’t dropped anything. Now it’s climbing, it’s going away! The engine doesn’t sound nearly so loud. Goodness, when we were standing out there at the edge of the quarry, I almost thought the plane would take my head off, it was so low!”

“I thought that too,” said Anne, very glad that there was to be no more swooping down and dropping dozens of unknown things. “Is it safe to go out?”

“Oh yes,” said Julian, scrambling out of the sand. “Come on. We shall easily hear if the plane comes back again. I want to see what it has dropped!”

In great excitement they ran to get the parcels. The stars gave so much light on that clear night that the four did not even need a torch.