"I feel so weak and dizzy," she answered. "And I'm afraid--oh, Allan, I'm afraid! But, no, I'm not hurt."
"Thank God for that!" he breathed fervently. "Can you untie these infernal knots? They're almost cutting my hands off!"
"Here, let me try!"
And presently the girl set to work; but even though she labored till her fingers ached, she could not start the tight and water-soaked ligatures.
"Hold on, wait a minute," directed he. "Feel in my right-hand pocket. Maybe they forgot to take my knife."
She obeyed.
"They've got it," she announced. "Even if they don't know the meaning of revolvers, they understand knives all right. It's gone."
"Pest!" he ejaculated hotly. Then for a moment he sat thinking, while the girl again tried vainly to loosen the hard-drawn knots.
"Can you find the iron door they shoved us through?" asked he at length.
"I'll see!"
He heard her creeping cautiously along the walls of stone, feeling as she went.
"Look out!" he warned. "Keep testing the floor as you go. There may be a crevice or pit or something of that kind."
All at once she cried: "Here it is! I've found it!"
"Good! Now, then, feel it all over and see if there's any rough place on it. Any sharp edge of a plate, or anything of that kind, that I could rub the cords on."
Another silence. Then the girl spoke.
"Nothing of that kind here," she answered depairingly. "The door's as smooth as if it had been filed and polished. There's not even a lock of any kind. It must be fastened from the outside in some way."
"By Heaven, this is certainly a hard proposition!" exclaimed the engineer, groaning despite himself. "What the deuce are we going to do now?"
For a moment he remained sunk in a kind of dull and apathetic respair.
But suddenly he gave a cry of joy.
"I've got it!" he exclaimed. "Your revolver, quick! Aim at the opposite wall, there, and fire!"
"Shoot, in here?" she queried, astonished. "Why--what for?"
"Never mind! Shoot!"
Amazed, she did his bidding. The crash of the report almost deafened them in that narrow room. By the stabbing flare of the discharge they glimpsed the black and shining walls, a deadly circle all about them.
"Again?" asked she.
"No. That's enough. Now, find the bullet. It's somewhere on the floor. There's no pit; it's all solid. The bullet--find the bullet!"
Questioning no more, yet still not understanding, she groped on hands and knees in the impenetrable blackness. The search lasted more than five minutes before her hand fell on the jagged bit of metal.