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 massive heavily-panelled 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.