The boy stood quite still for a while, listening. The sentry most obligingly cleared his throat and coughed again very loudly. Andy grinned. He made his way carefully round the end of the cliff and then began to climb up, feeling his way cautiously. The cliff there was not very steep, and Andy was soon at the top. He had not made a single sound.
He found a little hollow where heather and gorse grew thickly. He crept under an overhanging piece of bush, piled the heather beneath him, and slept peacefully. He knew he could do nothing till morning came, and he could see where he was.
The sun rose and Andy awoke. He was stiff and he stretched himself and yawned. He was hungry, but there was nothing for him to eat but bilberries.
He wriggled carefully to the edge of the cliff and looked over. Almost below him was the sentry he had heard last night, behind a rock at the cave-entrance. As Andy looked down he saw a boat coming to the shore, and a man stepped off, and walked up the beach to change places with the sentry. They stood talking for a while and then the first sentry went to the boat, yawning, and the new one settled down to his task of waiting and watching.
Andy sat and thought. He wriggled back to a place where he imagined he must be exactly over the Round Cave. He wondered if Tom could hear him, if he drummed on the ground with his feet. After all, the boy could not be very far below, for the Round Cave was fairly high up in the cliff.
And then a most extraordinary thing happened—so startling that Andy's heart jumped almost out of his body!
A groan came from somewhere under his legs! Andy was lying on the heather, and when the groan came, he shot his legs up beneath him and stared at the place where the groan had come from as if he simply couldn't believe his eyes or ears!
A smaller groan sounded, more like a long yawn. Andy stared at the heather, and wondered if his ears could be right! Heather couldn't yawn or groan! Then what was it?
Very cautiously and gently, the boy turned himself about and began to feel in the heather. He pulled it to one side, and to his enormous astonishment he found a hole below the roots of the heather—a hole that must lead down to the Round Cave for Andy reckoned that he must be exactly over that cave.
Andy felt so excited that he began to tremble. "No wonder that cave didn't smell as musty and stuffy as we expected it to," he thought. "There is an air-hole leading right down to it! Golly! I wonder if there's any chance of rescuing Tom this way."