"The Professor?" replied Nanette hastily. "Why, what should I know about it?"

"The Councillor was greatly excited and very unhappy when he discovered this affair, I suppose?"

"He is still."

"And how did he act after the--let us call it the accident?"

"He was like a crazy man."

"They tell me that he went about his duties just the same--that he went away on business."

"It wasn't business this time, at least not professional business. But before that he did have to go away frequently for weeks at a time."

"And it was then that your mistress was most interested in her lonely walks, eh?"

"Yes." Nanette's voice was so low as to be scarcely heard.

"Well, and this time?" continued the peddler. "Why did he go away this time?"

"He went to the capital on private business of his own."

"Are you sure of that?"

"Quite sure. He went two different times. I thought it was because he couldn't stand it here and wanted to see something different. He went to his club this evening, too."

"And when did he go away?"

"The first time was the day after his wife was buried."

"And the second time?"

"Two or three days after his return."

"How long did he stay away the first time?"

"Only one day."

"Good! Pull yourself together now. I'll send your George in to you and tell him you haven't been feeling well. Don't tell any one about our conversation. Where is the kitchen?"

"The last door to the right down the hall."

The peddler left the room and Nanette sank down dazed and trembling on the nearest chair. George found her still pale, but he seemed to think it quite natural that she should have been overcome by the recollection of the terrible death of her mistress. He gave the old man a most cordial invitation to return during the next few days. The cook brought the peddler a cup of steaming tea, and purchased several trifles from him, before he left the house.

When the old man had reached a lonely spot on the road, about half way between the hunting castle and the city, he halted, set down his pack, divested himself of his beard and his wig and washed the wrinkles from his face with a handful of snow from the wayside. A quarter of an hour later, Detective Muller entered the railway station of the city, burdened with a large grip. He took a seat in the night express which rolled out from the station a few moments later.

As he was alone in his compartment, Muller gave way to his excitement, sometimes even murmuring half-aloud the thoughts that rushed through his brain. "Yes, I am convinced of it, but can I find the proofs?" the words came again and again, and in spite of the comfortable warmth in the compartment, in spite of his tired and half-frozen condition, he could not sleep.

He reached the capital at midnight and took a room in a small hotel in a quiet street. When he went out next morning, the servants looked after him with suspicion, as in their opinion a man who spent most of the night pacing up and down his room must surely have a guilty conscience.

Muller went to police headquarters and looked through the arrivals at the hotels on the 21st of November. The burial of Mrs. Kniepp had taken place on the 20th. Muller soon found the name he was looking for, "Forest Councillor Leo Kniepp," in the list of guests at the Hotel Imperial. The detective went at once to the Hotel Imperial, where he was already well known. It cost him little time and trouble to discover what he wished to know, the reason for the Councillor's visit to the capital.

Kniepp had asked for the address of a goldsmith, and had been directed to one of the shops which had the best reputation in the city. He had been in the capital altogether for about twenty-four hours. He had the manner and appearance of a man suffering under some terrible blow.

Muller himself was deep in thought as he entered the train to return to his home, after a visit to the goldsmith in question. He had a short interview with Chief of Police Bauer, who finally gave him the golden bullet and the keys to the apartment of the murdered man. Then the two went out together.

An hour later, the chief of police and Muller stood in the garden of the house in which the murder had occurred. Bauer had entered from the Promenade after Muller had shown him how to work the lock of the little gate. Together they went up into the apartment, which was icy cold and uncanny in its loneliness. But the two men did not appear to notice this, so greatly were they interested in the task that had brought them there. First of all, they made a most minute examination of the two doors which had been locked. The keys were still in both locks on the inside. They were big heavy keys, suitable for the tall ma.s.sive heavily-paneled and iron-ornamented doors. The entire villa was built in this heavy old German style, the favourite fashion of the last few years.

When they had looked the locks over carefully, Muller lit the lamp that hung over the desk in the study and closed the window shutters tight.

Bauer had smiled at first as he watched his, protege's actions, but his smile changed to a look of keen interest as he suddenly understood.

Muller took his place in the chair before the desk and looked over at the door of the vestibule, which was directly opposite him. "Yes, that's all right," he said with a deep breath.

Bauer had sat down on the sofa to watch the proceedings, now he sprang up with an exclamation: "Through the keyhole?"

"Through the keyhole," answered Muller.

"It is scarcely possible."

"Shall we try it?"

"Yes, yes, you do it." Even the usually indifferent old chief of police was breathing more hastily now. Muller took a roll of paper and a small pistol out of his pocket. He unrolled the paper, which represented the figure of a French soldier with a marked target on the breast. The detective pinned the paper on the back of the chair in which Professor Fellner had been seated when he met his death.

"But the key was in the hole," objected Bauer suddenly.

"Yes, but it was turned so that the lower part of the hole was free.

Johann saw the light streaming through and could look into the room.

If the murderer put the barrel of his pistol to this open part of the keyhole, the bullet would have to strike exactly where the dead man sat.

There would be no need to take any particular aim." Muller gazed into s.p.a.ce like a seer before whose mental eye a vision has arisen, and continued in level tones: "Fellner had refused the duel and the murderer was crazed by his desire for revenge. He came here to the house, he must have known just how to enter the place, how to reach the rooms, and he must have known also, that the Professor, coward as he was--"

"Coward? Is a man a coward when he refuses to stand up to a maniac?"

interrupted Bauer.

Muller came back to the present with a start and said calmly, "Fellner was a coward."

"Then you know more than you are telling me now?"

Muller nodded. "Yes, I do," he answered with a smile. "But I will tell you more only when I have all the proofs in my own hand."

"And the criminal will escape us in the meantime."

"He has no idea that he is suspected."

"But--you'll promise to be sensible this time, Muller?"

"Yes. But you will pardon me my present reticence, even towards you?

I--I don't want to be thought a dreamer again."

"As in the Kniepp case?"

"As in the Kniepp case," repeated the little man with a strange smile.