Then after an interval, which seemed to her of grimly portentous length, it came again--the sound. There was no mistake that that was real. Equally certain was it that it came from the other side of the curtains, from the room which was empty, save for the mice and the man stretched out upon the table. No mouse, no gathering of mice, could have produced that sound; and the man on the table was dead. Was it possible that anyone could have come into the room without her knowledge? Surely she must have heard the opening of the door if it had been opened. She had noticed that the key turned in the lock with a grating noise, as if either the lock or the key were rusty. She was convinced that if the door had been opened she must have heard it; there was no other way into the room, yet she had heard that sound. It came a third time. Was it not someone breathing, or trying to breathe? It sounded like it. As if someone were gasping, struggling for breath, as if some too heavy sleeper were making a stertorous effort to wake out of slumber. If no one had come into the room--and how could anyone have come without her knowing it--who could it be? There was another point: such a noise could hardly come from a person who was in a normal condition. It had gone again; all was still, though she listened with all her ears, with every sense she had. Just as she was wondering if it had gone for good, hoping that it had, it came again--louder, more obvious, more terrible, than before. For there was a terrible quality in the noise itself, quite apart from the circumstances under which it was audible. A sensitive soul, hearing it in broad daylight, anywhere, would have shuddered; it had about it such a suggestion of physical discomfort: as though someone, spellbound in unwholesome sleep, strove to regain consciousness, in order to escape from some agonising nightmare, and strove in vain. Had Dorothy had any experience of modern medicine she would have recognised its likeness to the noise some surgical patients make as they gradually come back to life from the stupefying effects of some powerful anæsthetic.