For a quarter of an hour they shouted “Help!” at intervals of half a minute. No one came; nothing happened.
“It’s getting terribly stuffy, Jack,” she whispered.
“Yes, darling; I’m afraid it is,” he answered, steadily.
He was sitting on the arm of her chair—thinking desperately. Was there no way out? Was there nothing to be done?
“He can’t mean to kill us like this,” she cried, in despair.
He bent and kissed her gently, and she clung to him like a frightened child.
And so they sat for twenty minutes or more, till suddenly the girl clutched his arm.
“Jack,” she whispered, “look up. Oh, my God, look at him!”
She cowered back in the chair, and the man beside her, strong-nerved though he was, shuddered uncontrollably. For staring down on them from above, with his face pressed against the glass, was Hubert Garling. He was crawling over the smooth surface like some loathsome insect—gloating as he watched them.
Moved by an uncontrollable impulse, Jack Denver seized his discarded shoe and hurled it at the madman. So straight was the aim that they could see him start back; then, as the shoe dropped harmlessly back to the floor, Garling’s face once more pressed against the glass. And he was shaking with maniacal laughter.