The breaking of the twig was already explained. It was Johann Knoll who had stepped on it. But he had not climbed the wall at all, had only crept along it looking for a night’s shelter. And there was no connection between Knoll and the people who lived in the Thorne house. Muller had not the slightest doubt that the tramp had told the entire truth that day and the day preceding.
Then the detective’s mind went back to the happenings of Tuesday morning. The little twig had first drawn his attention to the Thorne estate and the people who lived there. He had seen the departure of the young couple and had passed the house again that afternoon and the following day, drawn to it as if by a magnet. He had not been able then to explain what it was that attracted him; there had been nothing definite in his mind as he strolled past the old mansion. But his repeated appearance had been noticed by some one—by one person only—the housekeeper. Why should she have noticed it? Had she any reason for believing that she might be watched? People with an uneasy conscience are very apt to connect even perfectly natural trivial circumstances with their own doings. Adele Bernauer had evidently connected Muller’s repeated passing with something that concerned herself even before the detective had thought of her at all.
Muller had not noticed her until he had seen her peculiar conduct that very morning. When he heard Franz’s words and saw how disturbed the woman was, he asked himself: “Why did this woman want to be shown the spot of the murder? Didn’t she know that place, living so near it, as well as any of the many who stood there staring in morbid curiosity? Did she ask to have it shown her that the others might believe she had nothing whatever to do with the occurrences that had happened there? Or was she drawn thither by that queer attraction that brings the criminal back to the scene of his crime?”
The sudden vision of Mrs. Bernauer’s head at the garden gate, and its equally sudden disappearance had attracted Muller’s attention and his thoughts to the woman. What he had been able to learn about her had increased his suspicions and her involuntary exclamation when she met him face to face in the house had proved beyond a doubt that there was something on her mind. His open accusation, her demeanour, and finally her swoon, were all links in the chain of evidence that this woman knew something about the murder in the quiet lane.
With this suspicion in his mind what Muller had learned from Knoll was of great value to him, at all events of great interest. Was it the housekeeper who had put out the light? For now Muller did not doubt for a moment that this sudden extinguishing of the lamp was a signal. He believed that Knoll had seen clearly and that he had told truly what he had seen. A lamp that is blown out by the wind flickers uneasily before going out. A sudden extinguishing of the light means human agency. And the lamp was lit again a few moments afterward and burned on steadily as before. A short time after the lamp had been put out the man had been seen going through the garden. And it could not have been much later before the shot was heard. This shot had been fired between the hours of nine and ten, for it was during this hour only that Knoll was in the garden house and heard the shot. But it was not necessary to depend upon the tramp’s evidence alone to determine the exact hour of the shot. It must have been before half past nine, or otherwise the janitor of No.1, who came home at that hour and lay awake so long, would undoubtedly have heard a shot fired so near his domicile, in spite of the noise occasioned by the high wind. There would have been sufficient time for Mrs. Bernauer to have reached the place of the murder between the putting out of the lamp and the firing of the shot. But perhaps she may have rested quietly in her room; she may have been only the inciter or the accomplice of the deed. But at all events, she knew something about it, she was in some way connected with it.
Muller drew a deep breath. He felt much easier now that he had arranged his thoughts and marshalled in orderly array all the facts he had already gathered. There was nothing to do now but to follow up a given path step by step and he could no longer reproach himself that he might have cast suspicion on an innocent soul. No, his bearing towards Mrs. Bernauer had not been sheer brutality. His instinct, which had led him so unerringly so many times, had again shown him the right way when he had thrust the accusation in her face.
Now that his mind was easier he realised that he was very hungry. He drove to a restaurant and ordered a hasty meal.
“Beer, sir?” asked the waiter for the third time.
“No,” answered Muller, also for the third time.
“Then you’ll take wine, sir?” asked the insistent Ganymede.