She ceased, for just then they heard the floor creak under a step downstairs. Rouletabille stopped Matrena short and drew his revolver. He wished to creep down alone, but he had not time. As the floor creaked a second time, Matrena’s anguished voice called down the staircase in Russian, “Who is there?” and immediately the calm voice of Natacha answered something in the same language. Then Matrena, trembling more and more, and very much excited keeping steadily to the same place as though she had been nailed to the step of the stairway, said in French, “Yes, all is well; your father is resting. Good-night, Natacha.” They heard Natacha’s step cross the drawing-room and the sitting-room. Then the door of her chamber closed. Matrena and Rouletabille descended, holding their breath. They reached the dining-room and Matrena played her dark-lantern on the sofa where the general always reclined. The sofa was in its usual place on the carpet. She pushed it back and raised the carpet, laying the floor bare. Then she got onto her knees and examined the floor minutely. She rose, wiping the perspiration from her brow, put the carpet hack in place, adjusted the sofa and dropped upon it with a great sigh.
“Well?” demanded Rouletabille.
“Nothing at all,” said she.
“Why did you call so openly?”
“Because there was no doubt that it could only be my step-daughter on the ground-floor at that hour.”
“And why this anxiety to examine the floor again?”
“I entreat you, my dear little child, do not see in my acts anything mysterious, anything hard to explain. That anxiety you speak of never leaves me. Whenever I have the chance I examine the flooring.”
“Madame,” demanded the young man, “what was your daughter doing in this room?”
“She came for a glass of mineral water; the bottle is still on the table.”
“Madame, it is necessary that you tell me precisely what Koupriane has only hinted to me, unless I am entirely mistaken. The first time that you thought to examine the floor, was it after you heard a noise on the ground-floor such as has just happened?”
“Yes. I will tell you all that is necessary. It was the night after the attempt with the bouquet, my dear little monsieur, my dear little domovoi; it seemed to me I heard a noise on the ground-floor. I hurried downstairs and saw nothing suspicious at first. Everything was shut tight. I opened the door of Natacha’s chamber softly. I wished to ask her if she had heard anything. But she was so fast asleep that I had not the heart to awaken her. I opened the door of the veranda, and all the police—all, you understand—slept soundly. I took another turn around the furniture, and, with my lantern in my hand, I was just going out of the dining-room when I noticed that the carpet on the floor was disarranged at one corner. I got down and my hand struck a great fold of carpet near the general’s sofa. You would have said that the sofa had been rolled carelessly, trying to replace it in the position it usually occupied. Prompted by a sinister presentiment, I pushed away the sofa and I lifted the carpet. At first glance I saw nothing, but when I examined things closer I saw that a strip of wood did not lie well with the others on the floor. With a knife I was able to lift that strip and I found that two nails which had fastened it to the beam below had been freshly pulled out. It was just so I could raise the end of the board a little without being able to slip my hand under. To lift it any more it would be necessary to pull at least half-a-dozen nails. What could it mean? Was I on the point of discovering some new terrible and mysterious plan? I let the board fall back into place. I spread the carpet back again carefully, put the sofa in its place, and in the morning sent for Koupriane.”
Rouletabille interrupted.
“You had not, madame, spoken to anyone of this discovery?”
“To no one.”
“Not even to your step-daughter?”
“No,” said the husky voice of Matrena, “not even to my step-daughter.”
“Why?” demanded Rouletabille.
“Because,” replied Matrena, after a moment’s hesitation, “there were already enough frightening things about the house. I would not have spoken to my daughter any more than I would have said a word to the general. Why add to the disquiet they already suffered so much, in case nothing developed?”
“And what did Koupriane say?”
“We examined the floor together, secretly. Koupriane slipped his hand under more easily than I had done, and ascertained that under the board, that is to say between the beam and the ceiling of the kitchen, there was a hollow where any number of things might be placed. For the moment the board was still too little released for any maneuver to be possible. Koupriane, when he rose, said to me, ‘You have happened, madame, to interrupt the person in her operations. But we are prepared henceforth. We know what she does and she is unaware that we know. Act as though you had not noticed anything; do not speak of it to anyone whatever—and watch. Let the general continue to sit in his usual place and let no one suspect that we have discovered the beginnings of this attempt. It is the only way we can plan so that they will continue. All the same,’ he added, ‘I will give my agents orders to patrol the ground-floor anew during the night. I would be risking too much to let the person continue her work each night. She might continue it so well that she would be able to accomplish it—you understand me? But by day you arrange that the rooms on the ground-floor be free from time to time—not for long, but from time to time.’ I don’t know why, but what he said and the way he said it frightened me more than ever. However, I carried out his program. Then, three days later, about eight o’clock, when the night watch was not yet started, that is to say at the moment when the police were still all out in the garden or walking around the house, outside, and when I had left the the ground-floor perfectly free while I helped the general to bed, I felt drawn even against myself suddenly to the dining-room. I lifted the carpet and examined the floor. Three more nails had been drawn from the board, which lifted more easily now, and under it, I could see that the normal cavity had been made wider still!”
When she had said this, Matrena stopped, as if, overcome, she could not tell more.
“Well?” insisted Rouletabille.
“Well, I replaced things as I found them and made rapid inquiries of the police and their chief; no one had entered the ground-floor. You understand me?—no one at all. Neither had anyone come out from it.”
“How could anyone come out if no one had entered?”
“I wish to say,” said she with a sob, “that Natacha during this space of time had been in her chamber, in her chamber on the ground-floor.”
“You appear to be very disturbed, madame, at this recollection. Can you tell me further, and precisely, why you are agitated?”
“You understand me, surely,” she said, shaking her head.
“If I understand you correctly, I have to understand that from the previous time you examined the floor until the time that you noted three more nails drawn out, no other person could have entered the dining-room but you and your step-daughter Natacha.”
Matrena took Rouletabille’s hand as though she had reached an important decision.
“My little friend,” moaned she, “there are things I am not able to think about and which I can no longer entertain when Natacha embraces me. It is a mystery more frightful than all else. Koupriane tells me that he is sure, absolutely sure, of the agents he kept here; my sole consolation, do you see, my little friend can tell you frankly, now that you have sent away those men—my sole consolation since that day has been that Koupriane is less sure of his men than I am of Natacha.”
She broke