as in excitement over the mystery, even the police
station was shaken out of its usual business-like indifference. There
was no other topic of conversation in any of the rooms but the
mystery of the golden bullet and the doors closed from the inside. The
attendants and the policeman gathered whispering in the corners,
and strangers who came in on their own business forgot it in their
excitement over this new and fascinating mystery.

That afternoon Muller passed through Horn's office with a bundle of
papers, on his way to the inner office occupied by his patron, Chief of
Police Bauer. Horn, who had avoided Muller since yesterday although he
was conscious of a freshened interest in the man, raised his head and
watched the little detective as he walked across the room with his
usual quiet tread. The commissioner saw nothing but the usual humble
business-like manner to which he was accustomed--then suddenly
something happened that came to him like a distinct shock. Muller
stopped in his walk so suddenly that one foot was poised in the air. His
bowed head was thrown back, his face flushed to his forehead, and the
papers trembled in his hands. He ran the fingers of his unoccupied hand
through his hair and murmured audibly, "That dog! that dog!" It was
evident that some thought had struck him with such insistence as to
render him oblivious of his surroundings. Then he finally realised where
he was, and walked on quickly to Bauer's room, his face still flushed,
his hands trembling. When he came out from the office again, he was his
usual quiet, humble self.

But the commissioner, with his now greater knowledge of the little man's
gifts and past, could not forget the incident. During the afternoon
he found himself repeating mechanically, "That dog--that dog." But the
words meant nothing to him, hard as he might try to find the connection.

When the commissioner left for his home late that afternoon, Muller
re-entered the office to lay some papers on the desk. His duties over,
he was about to turn out the gas, when his eye fell on the blotter on
Horn's desk. He looked at it more closely, then burst into a loud
laugh. The same two words were scribbled again and again over the white
surface, but it was not the name of any fair maiden, or even the title
of a love poem; it was only the words, "That dog--"

Several days had passed since the discovery of the murder. Fellner had
been buried and his possessions taken into custody by