The Signora Petito paled and rose to her feet; Signor Petito rose to his feet paler still. "The hour has come!" said the Signora Petito. "You will find the information you want below." She pointed a rigid finger at the floor. "They cannot hear you in your list slippers. Besides, there's no danger of it: they are at Esbly." Two minutes later a dark figure glided down to M. Longuet's flat, slipped a key into the lock of his door, and entered his hall. The flat of Theophrastus was of exactly the same construction as that of Signor Petito, and he found his way into the dining-room without a pause. He acted with the greater coolness because he believed that the flat was empty. He opened the door of the study, and saw the violet cat on the bureau. Since it was evidently on the lock of the bureau in which he was interested, he took it up, and set it on the tea-table. Then he hurried noiselessly back through the dining-room into the hall, for he fancied he heard voices on the staircase. He listened for a while at the door of the flat and heard nothing; doubtless his ears had deceived him. Then he came back to the study. He found _the violet cat on the bureau, purring_. In spite of their crinkliness, the hairs of Signor Petito stood stiffly upright on his head, the horror which filled him can only be compared to that other horror on the other side of the wall. He stood motionless, panting, in the moonlight, even after the little violet cat had stopped purring. Then he braced himself, and with a timid hand picked up the violet cat. As soon as he had moved it, it began to purr; and he became acquainted with the fact that in its cardboard interior there was a small marble which, as it rolled to and fro, produced an ingenious imitation of a natural purr. Since he had been frightened to death, he called himself a perfect fool. It was all quite clear; had he not before slipping out of the study moved the cat? Instead of having set it on the tea-table, as he thought, he had put it back on the bureau. Of course, it was quite simple. He set it back, still purring, on the tea-table. It must not be forgotten that this purring, which did not terrify Signor Petito, terrified Theophrastus and his wife afresh, while the second purring, which had taken the curl out of Signor Petito's hair with terror, had not terrified them at all. The cat was still purring, when there was another noise outside the flat. It was Signora Petito sneezing in the draught. Signor Petito hurried back into the hall and once more glued his ear to the door of the flat. When, reassured, he returned to the study, _the purring violet cat had gone back to the bureau_.