The moon was shining full into the choked entrance now, but they could not see far inside. Even as Dickie came in out of the moonlight it seemed from somewhere there came again the mysterious sound of phantom voices. Macbeth barked and whined in the darkness, and then rushed excitedly back to the children. Mary grabbed at him, but Dickie was feeling the rock that moved.

"It's peculiar, Mary, but it does move. You're right. What a funny great stone. P'raps it's balanced on something like the stone doors that used to guard treasure and only moved when you said the magic word. Let's try a word... Open, SESAME! No good! I didn't think that would do. Oh, gosh, Mary! It's moving a lot. Feel! GOSH! IT ROCKS! It's rocking now... Let's give it a real push!..."

They both pushed and pushed too hard. There was an ear-splitting crash as the balancing rock swayed and then fell sideways across the entrance.

Except for a few fugitive gleams, the cave was now dark and the way out was barred.

Mary cried, "What have we done?" and Dickie, "Gosh! that surprised us, didn't it? 'Spect that was a trap really." But his voice broke on the last sentence, and only once before did he remember being so frightened. Macbeth whined at their feet and the twins clutched each other as the silence, like the darkness, closed round them.

9. The Cable

Macbeth's sudden appearance at the entrance of the mine affected Peter, David and Jenny very differently. Peter was the first to see him. "It's Mackie!" she whispered. "I know it is and he's wearing Mary's bow. I grumbled at her last night for not taking it off when she went to bed... I think they've sent him as a messenger."

Jenny squealed excitedly, "He must be haunted. He's come from nowhere," but David called quietly, "Come here, Mackie."

The little dog watched them with interest and slowly wagged his tail. David called him again, and rather condescendingly he ambled over, jumped up to lick David's bare knee, and then rolled on his back to have his chest tickled.

"It's Mac right enough," said David, as he accepted the dog's invitation. "Are you sure about the ribbon, Peter?"

"Yes, of course I am. I know Mary was wearing it when she went to bed, and this proves that Mackie has been with them. They must be somewhere near..."

"Let's call them," said Jenny. "Let's shout and shout!"

But David was looking fixedly at the cliff face, and the opening above where the wires of the railway cable disappeared. Then he ran over to the rocks below, went down on his knees and peered into the narrow opening.

"Mackie might have come through here," he called excitedly. "It looks as if there's a narrow tunnel through these rocks, but it's not big enough for the twins. You saw him first, didn't you, Peter? Did he actually come out of this tunnel?"