“Well, then,” said I, “all we have to do is to summon Leonard and hear what he has to say concerning this affair.  He will surely know whether or not his master went into the house next door.”

“Leonard has left us,” she said.  “Dr. Zabriskie has another chauffeur now.  Besides (I have nothing to conceal from you), Leonard was not with him when he returned to the house that evening or the doctor would not have been without his portmanteau till the next day.  Something—­I have never known what—­caused them to separate, and that is why I have no answer to give the doctor when he accuses himself of committing a deed that night so wholly out of keeping with every other act of his life.”

“And have you never asked Leonard why they separated and why he allowed his master to come home alone after the shock he had received at the station?”

“I did not know there was any reason for my doing so till long after he had left us.”

“And when did he leave?”

“That I do not remember.  A few weeks or possibly a few days after that dreadful night.”

“And where is he now?”

“Ah, that I have not the least means of knowing.  But,” she objected, in sudden distrust, “what do you want of Leonard?  If he did not follow Dr. Zabriskie to his own door, he could tell us nothing that would convince my husband that he is labouring under an illusion.”

“But he might tell us something which would convince us that Dr. Zabriskie was not himself after the accident; that he—­”

“Hush!” came from her lips in imperious tones.  “I will not believe that he shot Mr. Hasbrouck even if you prove him to have been insane at the time.  How could he?  My husband is blind.  It would take a man of very keen sight to force himself into a house closed for the night, and kill a man in the dark at one shot.”

“On the contrary, it is only a blind man who could do this,” cried a voice from the doorway.  “Those who trust to eyesight must be able to catch a glimpse of the mark they aim at, and this room, as I have been told, was without a glimmer of light.  But the blind trust to sound, and as Mr. Hasbrouck spoke—­”

“Oh!” burst from the horrified wife, “is there no one to stop him when he speaks like that?”

III

As you will see, this matter, so recklessly entered into, had proved to be of too serious a nature for me to pursue it farther without the cognizance of the police.  Having a friend on the force in whose discretion I could rely, I took him into my confidence and asked for his advice.  He pooh-poohed the doctor’s statements, but said that he would bring the matter to the attention of the superintendent and let me know the result.  I agreed to this, and we parted with the mutual understanding that mum was the word till some official decision had been arrived at.  I had not long to wait.  At an early day he came