sufficient proof that his
death had been an act of vengeance. But who was it who had carried out
this secret, terrible deed? The victim had not been allowed the time to
write down the name of his murderer.

Horn took the letter into his keeping. Then he left the room, followed
by Muller and the valet, to look about the rest of the house as far as
possible. This was not very far, for the second story was closed off by
a tall iron grating.

"Is the house door locked during the daytime?" asked Horn of the
servant.

"The front door is, but the side door into the garden is usually open."

"Has it ever happened that any one got into the house from this side
door without your knowing it?"

"No, sir. The garden has a high wall around it. And there is extra
protection on the side toward the Promenade."

"But there's a little gate there?"

"Yes, sir."

"Is that usually closed?"

"We never use the key for that, sir. It has a trick lock that you can't
open unless you know how."

"You said you went to the theatre yesterday evening. Did your master
give you permission to go?"

"Yes, sir. It's about a year now that he gave me money for a theatre
ticket every Saturday evening. He was very kind."

"Did you come into the house last night by the front door, or through
the garden?"

"Through the garden, sir. I walked down the Promenade from the theatre."

"And you didn't notice anything--you saw no traces of footsteps?"

"No, sir. I didn't notice anything unusual. We shut the side door, the
garden door, every evening, also. It was closed yesterday and I found
the key--we've only got one key to the garden door--in the same place
where I was told to hide it when I went out in the evening."

"What place was that?"

"In one of the pails by the well."

"You say you were told to hide it there?"

"Yes, sir; the Professor told me. He'd go out in the evening sometimes,
too, I suppose, and he wanted to be able to come in that way if
necessary."

"And no one else knew where the key was hidden?"

"No one else, sir. It's nearly a year now that we've been alone in the
house. Who else should know of it?"

"When you looked through the keyhole last night, are you sure that the
Professor was still alive?"

"Why, yes, sir; of course I couldn't say so surely. I thought he was
reading or writing, but oh, dear Lord! there he was this morning, nearly
twelve hours later, in just the same position." Johann shivered at the
thought t