The lamp above was burning brightly, and she could see every detail of the compartment, except towards the floor.

As she gazed a man's back slowly rose; he appeared to have been kneeling on the floor, and he held in his hand the loop of a rubber tube.

Peering downwards, she saw that it was connected with the cylinder, and that it was undoubtedly pouring whatever gas the cylinder contained through the hole into Room A.For a moment she had difficulty in repressing a shriek; but realizing how perfectly helpless she was, even if an alarm were raised, she fought down all exclamation.

She saw that the man who was regulating the escape of gas was not the one who had spoken to the conductor.

Then, fearing that he might turn his head and see her eye at the small aperture, she reached up and covered the lamp, leaving her own room in complete darkness.