He knew that he was in a most dangerous position, for if the sheep were to go in through the gates they would have to be driven up the side of the bank. There was no chance for him to move, for if he attempted to do so surely either the man or the dog would see him? In despair he tried to wriggle still lower into the heather and wondered, if his luck held, how he would be able to follow the flock into Grey Walls when the gates were opened.

But now came the greatest surprise of all. He could hear the man below him cursing the sheep and his dog, and the sound of his stick as he struck some of the frightened and bewildered animals. Then, when he plucked up his courage to raise his head again, he saw the man bending down over something at ground level on the far side of the ditch. Although this side of the dyke was in shadow, it seemed to him that the man lifted something and then stood to one side. Tom strained his eyes, but could see nothing more than a darker patch of shadow which might perhaps be a rectangular hole in the bank.

It was a hole in the bank! He almost yelled in excitement as the dog barked again from further down the track, the man shouted and used his stick and the sheep began to vanish, one by one, into the cavity.

This then, was the secret of Grey Walls!

Tom peered down into the shadows and was just able to distinguish the form of the stranger as he got into the hole backwards and pulled the cover across the entrance again from the inside.

He lay still and listened. From the other side of the wall came the slightly muffled sound of the bleating sheep and the sharp, excited bark of the dog. There was just a chance, Tom thought, that the shepherd had not followed his flock and might still be in the ditch, so he waited for a few minutes before sliding down the bank. He was too excited now to remember David or Jon or any of the others! This was a thousand times better than any film which he had ever seen, and he was determined to make the most of it and this wonderful chance to get inside Grey Walls.