The detective entered the hall, then said:
“Now, please be kind enough to tell me positively if the professor is in?”
“I don’t know.”
“Yes, you do.”
“I say I don’t.”
“And I know better. If he is in I promise you he will see me, while if he is out I will not waste my time waiting for your red tape.”
The servant was rather taken aback by this plain talk, and for a moment hardly knew what to say.
Then the half-laughing reply was made:
“While I cannot say positively, I think he is.”
“Are you not quite sure that he is?”