The wall was smooth and apparently solid. Suddenly he put out his foot and stepped upon nothing but air. He tried to draw back, but it was too late, and with a cry that could not be suppressed he went down into pitch-black space. He struck on some sharp rocks, and then his senses forsook him.
The fall was a perilous one and it was only by good luck that Adam Adams did not have his brains dashed out. As it was he remained unconscious for fully half an hour, and came to his senses to find a large lump on his head and the blood flowing over his face. His left shoulder was lame and for the time being he was afraid it was broken.
The rocks upon which he had fallen rested in several inches of water, and with this water he washed off the blood and bathed his hurts as best he could in the darkness.
The mishap made him reach but one conclusion. Matlock Styles had placed him there so that he might injure if not kill himself!
"The rascal!" muttered the detective. "If I ever get out of here he shall suffer for this if for nothing else!"
It took him some time to pull himself together and get his breath. Then he felt around cautiously, being careful to take no more steps until he was sure of his footing.
In a quarter of an hour he knew he was a prisoner in a circular cistern perhaps twelve feet in diameter and of uncertain depth. The walls were perpendicular, smooth and covered with slime, so to crawl up was totally out of the question.
"A pretty fix to be in," he mused. "If Styles had wanted to kill and bury me he couldn't have started out better. Ha! What's that?" He listened and then smiled grimly to himself. "Rats. I suppose there are scores of them around this place. I must see to it that they don't get a chance to feed upon my body!"
What was the best way to get out? For some minutes the detective studied the situation. In one of his pockets he had stuffed the rope taken from his legs, thinking it might come in handy in some way. He made a small loop at one end of this rope and threw it upward a dozen times or more. At last it caught on something and held fast.
Being on guard, in case he might fall backward, Adam Adams pulled himself up on the rope. It had caught on a sharp stone close to the top of the cistern and with an effort he drew himself to the flooring above.