After a few minutes they came to a little wood and, once through this, they saw the ruins of the cottages close under the cliff. As Jenny had said, the ruins were unpleasant, but they had to be explored. They called and whistled and pushed their way over the piles of broken stones and nettles, but could find no sign that the twins had been this way. Bats fluttered helplessly as they spoke briefly to each other in an effort to break an eerie silence, and suddenly Jenny said in a choky voice, "I hate this place. Come away. It's vile."

The others did not like it either, but David would not leave until he had satisfied himself that there was nothing to find. Most of the cottages had been little more than hovels, but three of them had a room upstairs, and after a meaning look at the stubborn Jenny, who had removed herself to the edge of the clearing, he led the way back to the nearest ruin. In this one half the steep staircase had collapsed, but he jumped for the edge of the top stair and hauled himself up as if he was in the gym. at school. He was sure that he would find nothing, but felt he must now search every square inch that he had missed the first time. But he found only dust and rotting floorboards and the droppings of birds. The second cottage was like the first, and at the third he managed to pull Peter up beside him as a huge grey rat scuttled across the floor. But there was nothing to find - no clues. Not even a 'mastock'. When they came out into the open again he looked at his watch and saw that it was past twelve.

"We'll just go up to the edge of the cliff before we eat," he said. "I can see now where the wires go in. Look! There's a crack in the rock just above what looks like quite a big cave... And the path seems to lead there, too. Let's try it. We must go everywhere now we're here."

So they trudged on and the path began to zig-zag as it climbed towards the cliff. After a while it brought them to a little grassy plateau, and for the first time was disclosed an entrance to a big cave which now seemed blocked by an enormous mass of rock. Above this was another hole in the rock face looking rather like a big window, and through this the wires of the cable railway disappeared. David turned to emphasise the discovery, but before he could speak Peter seized his arm and pointed. Coming sedately into the sunshine from the shadowed entrance of the old mine was a small black dog. He was wearing a bow of bright green ribbon round his neck and, at the sound of voices, he stopped, cocked his head and lifted one paw.