Mary shook her head and then lifted up Mackie. They could see that she was shouting, but her voice was not strong enough to be heard, so, still muttering, David turned and floundered back towards her.

"Hurry on, Jon," he called as he passed, "and take Dickie with you... See if you can catch them before they start the car."

But Dickie insisted on going back with David for Mary, and there was so much confusion and argument that precious time was wasted.

Mary explained that Mackie did not like salt water and would not even swim through it, and she refused to cross the pool herself unless Penny carried the dog. David then took Mary on his back and Jon took Dickie, while poor Penny had to flounder through the water as best she could with Macbeth snuggled under her arm.

As soon as they were all safely over, Jon and David raced ahead to the foot of the hill, but they were too late - far down the rough track that led to the road they saw the red tail-light of a car. They could not be certain that it was Miss Ballinger's, but there was no doubt that this was the last car to leave the beach and that they would have to trudge back to Winchelsea and safety.

"I doubt if these kids will make it," David said. "If Mary hadn't played the fool over the dog we would have caught them up."

Jon nodded. "I know. Do you realize that the Ballinger would have left the twins and Penny there in that place?... Look, David! The car has disappeared now, but there's something coming towards us down the track now... It's another big lorry loaded with faggots."

So they stood for a few minutes, a lonely little group at the foot of the hill. The rain had stopped and the rising moon gleamed sometimes through the gaps in the racing clouds, but all the air was filled with the mighty thunder of the waves behind them. They watched the lorry lurching towards them, and David wondered if perhaps they could wait until it was unloaded and then get a lift back to Winchelsea. Then the moon came out from behind a cloud again and a man standing on the lorry suddenly waved his arms and shouted.

"He's pointing at us," Mary said. "He's shouting... What do we do next, David?"

"Look!" David shouted. "Watch the bank. I saw it move. Something's happened to it... it's changing shape..."

Penny shouted against the noise almost without realizing what she was saying, clutched Mary close to her and screamed.

"It's breaking... The sea's coming through!"

The next few moments were like a nightmare - a nightmare in which something terrifying rushes towards the dreamer who cannot move to save himself and then, at the very last instant, wakes. But none of them could wake now, although it must have been a minute before Jon shouted: