Then the man seemed to be gathering himself for an effort; he applied his lips to the burner and remained motionless and tense; suddenly the picture upon the lawn dimmed and then vanished entirely.

For an instant Ashton-Kirk remained looking out upon the now inky night; if one could have observed his face, a smile would have been seen; but a smile that would not have been an altogether pleasant one.

"It is not the most comforting thing in the world," he mused, "to have one person beckon another along a deserted hall in the small hours of the morning, have the couple pause almost outside one's door and then confer as to the most effective means of taking one's life. And that the one—a woman—should be so urgent in the matter is particularly distressing." He turned from the window and faced toward the closed door of his bedroom. "And a ready-witted young lady she is," he went on. "How very quick she was to note that the gas was burning in my room; and what an instant and murderous idea at once took possession of her. To blow into an open gas-burner means that every jet upon the same line of pipe will go out as soon as the injected air instead of the gas begins to flow through the burners. About now I shall find the light out in my room and," here he opened the bedroom door, saw that it was in complete darkness and stood sniffing the air upon the threshold, "yes, the gas is pouring from the open burner. If I had been asleep——"

The apartment was thick with the overpowering fumes; he softly raised the windows and closed the valve. It would have seemed natural for a man so circumstanced to have taken some steps to identify and apprehend those who have made so murderous an attempt; but if this thought occurred to Ashton-Kirk he made no attempt to carry it out. However, another idea occurred to him.

"The old woman said that there were nothing but gaslights above the first floor. If another jet should be open in an occupied bedroom, there is still danger of a life being taken."

With this in his mind he pulled on his coat and opened the hall door. There were no fumes in the hall, and this showed that the burners here had been closed before the two had stolen away. He took out a match and was feeling for the nearest of the hall jets when a sound from the lower floor reached him. It was a continued, grating sort of noise, as though a cautious person were drawing a refractory bolt. He paused, his groping hand still outstretched, and listened with attention. The subdued squeaking ceased, there was a pause, then the street door opened and closed. He took a step or two toward the main staircase, and again he halted. Another sound came from below, the distinct, heavy sounds of falling objects striking the floor. Then came a shrill cry.

Like a shadow he slipped along the intervening space, and down the stairs. The lower hall was also dark; but there was a light in the library, and he gained the door at a bound.

Old Nanon, dressed as he had seen her when she showed him to his room, stood in the center of the library. In her hand she held a large brass candlestick; scattered upon the floor were a number of articles of bric-à-brac which had apparently rested upon a shelf at one side.

Slowly the woman turned her gaze from the candlestick to the secret agent; her face was rigid and a yellowish white; the gray eyes were hard as flint.