He quickly hung up the receiver and turned on his heel to leave the telephone box. The next moment he had flung himself against the farther wall. Just as he was about to pass out he had heard something click above his head and he but barely had the time to leap back and escape being struck by an iron curtain which fell in front of him with a terrible thud.
Another second and the huge mass would have crushed him. He could feel it whizzing by his head. And he had never before experienced the anguish of danger so intensely.
After a moment of genuine fright, in which he stood as though petrified, with his brain in a whirl, he recovered his coolness and threw himself upon the obstacle. But it at once appeared to him that the obstacle was unsurmountable.
It was a heavy metal panel, not made of plates or lathes fastened one to the other, but formed of a solid slab, massive, firm, and strong, and covered with the sheen of time darkened here and there with patches of rust. On either side and at the top and bottom the edges of the panel fitted in a narrow groove which covered them hermetically.
He was a prisoner. In a sudden fit of rage he banged at the metal with his fists. He remembered that Mlle. Levasseur was in the study. If she had not yet left the room—and surely she could not have left it when the thing happened—she would hear the noise. She was bound to hear it. She would be sure to come back, give the alarm, and rescue him.
He listened. He shouted. No reply. His voice died away against the walls and ceiling of the box in which he
