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