I looked at him sternly, and Thorndyke, quite unmoved by his indecorous behaviour, said in a grave voice: "Let me introduce you, Jervis; though I think you have met this gentleman before." "I think not," I said stiffly.
"Oh yes, you have, sir," interposed the stranger; and, as he spoke, I started; for the voice was uncommonly like the familiar voice of Polton.
I looked at the speaker with sudden suspicion.

And now I could see that the flaxen hair was a wig; that the beard had a decidedly artificial look, and that the eyes that beamed through the spectacles were remarkably like the eyes of our factotum.

But the blotchy face, the bulbous nose and the shaggy, overhanging eyebrows were alien features that I could not reconcile with the personality of our refined and aristocratic-looking little assistant.
"Is this a practical joke ?" I asked.
"No," replied Thorndyke; "it is a demonstration.

When we were talking this morning it appeared to me that you did not realize the extent to which it is possible to conceal identity under suitable conditions of light.

So I arranged, with Polton's rather reluctant assistance, to give you ocular evidence.