“Why may I be late to-morrow?” I asked.
“I have a message for you from the doctor,” he replied. “It is about what you were discussing last night. He told me to tell you that he is expecting a visit from an officer of the Criminal Investigation Department, and he would like you to be present, if it would be convenient. About half-past ten, Sir.”
“I will certainly be there,” said I.
“Thank you, Sir,” said he. “And the doctor told me to warn you, in case you should arrive after the officer, not to make any comment on anything that may be said, or to seem to know anything about the subject of the interview.”
“This is very mysterious, Polton,” I remarked.
“Why, not particularly, Sir,” he replied. “You see the officer is coming to give certain information, but he will try to get some for himself if he can. But he won’t get anything out of the doctor; and the only way for you to prevent his pumping you is to say nothing and appear to know nothing.”
I laughed at his ingenuous wiliness. “Why,” I exclaimed, “you are as bad as the doctor, Polton. A regular Machiavelli.”
“I never heard of him,” said Polton, “but most Scotsmen are pretty close. Oh, and there is another little matter that I wanted to speak to you about—on my own account this time. I gathered from the doctor, in confidence, that some one had been following you about. Now, Sir, don’t you think it would be very useful to be able to see behind you without turning your head?”
“By Jove!” I exclaimed. “It would indeed! Capital! I never thought of it. I will have a supplementary eye fixed in the back of my head without delay.”
Polton crinkled deprecatingly. “No need for that, Sir,” said he. “I have invented quite a lot of different appliances for enabling you to see behind you; reflecting spectacles and walking sticks with prisms in the handle, and so on. But for use at night I think this will answer your purpose best.”