Holmes handed me a card upon which was printed: “ Dr. Hill Barton, 369 Half Moon Street.”

“That is your name for the evening, Watson. You will call upon Baron Gruner. I know something of his habits, and at half-past eight he would probably be disengaged. A note will tell him in advance that you are about to call, and you will say that you are bringing him a specimen of an absolutely unique set of Ming china. You may as well be a medical man, since that is a part which you can play without duplicity. You are a collector, this set has come your way, you have heard of the Baron’s interest in the subject, and you are not averse to selling at a price.”

“What price?”

“Well asked, Watson. You would certainly fall down badly if you did not know the value of your own wares. This saucer was got for me by Sir James, and comes, I understand, from the collection of his client. You will not exaggerate if you say that it could hardly be matched in the world.”