The words of old Nanon, spoken only a few hours before, came back to Ashton-Kirk.

"It will be so much safer to have a man about the place, even though a sick one," she had said. "Now that Drevenoff is gone for the night, we should have been alone."

The two shadows remained with heads held close together for some little time. It was plain to be seen that the woman was doing the greater part of the talking; the man gestured now and then as though in protest.

"She is urging him to something which he does not fancy," thought the secret agent, his keen eyes not missing a movement. "And, as his denials constantly grow fainter, and her urging more insistent, I think she will finally have her way."

Fancifully the two silhouettes went through their parts within the lighted square as cast by the gaslight upon the lawn. The woman pleaded and demanded; the man resisted with wide gestures and violently shaken head.

But, as the secret agent had told himself, the woman proved herself the stronger in the end. Sharp, imperious, even threatening grew her manner; and the man's protests died, his head ceased to shake, until finally his gestures were inquiring only, as of one who consents and desires only to know the best way of going about the matter in hand.

At this stage the shadow of the woman became still for the first time since it had appeared. It were as though she were endeavoring to recall something, or devise a plan. Then with an impatient gesture she snatched at a hand-bag which hung upon her arm and seemed about to open it. But with a contemptuous sweep of the hand the man waved it aside.

Again the two began their mute debate. This time it was the man who took the initiative; she had failed when she came to the carrying out of what she desired; apparently she had no clear conception of the thing she wanted done, and he was reproaching her for it.

But in the midst of this she stopped him. Her hand darted out, and from the wall she drew something, the shadow of which was so fine that Ashton-Kirk could not, at first, even guess as to its nature. But the way it swung out at her touch finally gave him a clue.

"A folding gas fixture," said he, softly.

Once more the girl took the aggressive; she gestured sharply and indicated frequently a point upon her left, some distance along the hall, and apparently a little above her head. The silhouette of the man remained motionless; what he heard was evidently bearing in upon him; his whole attitude seemed to say: "Here at last is something worth consideration."

Then there was a pause; the woman also became still; it were as though the two were measuring each other's strength. At length the man stepped toward the gas fixture, the woman drew back, and as she did so her hands went to her face as though she would shut out something repellent. With a handkerchief, the man brushed away any possible dust from the gas-burner; then he reached toward where the valve should be, and the half twist of his hand indicated that he had turned on the gas.

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.

"Ah, it is you," she said in a sort of subdued monotone. "I had forgotten about you."

"What has happened?" asked Ashton-Kirk.

The eyes of the servant woman once more returned to the candlestick, but she made no answer.

"I heard some one cry out," said the secret agent, his glance going about the room in its searching way.

Nanon nodded her head.

"Yes," she returned, "you heard some one cry out. It was I."

"What has occurred?"

Once more the stern old eyes sought his face; and she said:

"She has gone."

"Who has gone?"

"Miss Stella."

Ashton-Kirk thought of the creaking bolt and the closing street door; and his voice was pitched sharply when he again asked the question:

"What has occurred?"

The old servant placed the brass candlestick upon one of the desks; she rubbed her hands secretively with a corner of her apron while she said:

"I have told you what I fear; I have been as plain as one can be who has no proof. And as the hours passed I have grown more and more suspicious. Not one movement did this girl make that my eyes were not on her; not one word did she speak that I was not seeking behind it for some hidden meaning.

"To-night, as you know, she sent Drevenoff to the city. It was something of which I had heard nothing until the young man spoke. What was this urgent thing that could not wait until morning? Why would not the telephone or telegraph do as well as a messenger? I did not understand it. And then she did not care to have you stay here to-night; that was very plain—you must have noticed it."

Ashton-Kirk nodded.

"Go on," said he.

"It does not need a great deal to make me suspicious," resumed the old woman; "and her manner to-night aroused me to wonder if there were not something afoot of which I knew nothing. So when I went to my room I put out the light, left the door ajar and sat listening. After a long time I knew there was a light in the hall below; I stole out and bent over the rail and listened. There was whispering, but I could catch no words. Then I heard some one descending the lower staircase; and so I stole down to the second floor. From the head of the stairs I watched once more; then I saw the light go up here in the library.

"I had already started to descend when Miss Stella appeared in the library doorway—and in her hand she held," the speaker pointed at the desk, "that candlestick."

Here the old woman paused; and the secret agent, watching her face, saw the yellowish white change to gray.

"Well?" said he.

"She looked along the hall as if afraid of being seen," said the woman; "and all the time her fingers were picking—picking at something in the socket of the candlestick. She was just turning back into the room when she drew something out, looked at it and hid it in her glove. Then the light went out and I heard the bolt being drawn. I rushed down the stairs, but I was too late. The door opened and closed; I turned on the lights, but she was gone."

For a moment Ashton-Kirk stood studying the woman's face; then he stepped quickly to the desk and took up the candlestick. Something in the deep socket of this seemed to attract him and he turned on more lights. Under a cluster of incandescents he bent over the candlestick and examined it minutely; then the magnifying lens came into play as it had upon the broken knob of the highboy. One glance through this and he sprang to the street door. The next instant a piercing whistle shattered the quiet of Fordham Road.