"But this danger, Holmes?"
"Ah, yes; in case it should come off, it would perhaps be as well that you should burden your memory with the name and address of the murderer. You can give it to Scotland Yard, with my love and a parting blessing. Sylvius is the name—Count Negretto Sylvius. Write it down, man, write it down! 136 Moorside Gardens, N.W. Got it?"
Watson's honest face was twitching with anxiety. He knew only too well the immense risks taken by Holmes, and was well aware that what he said was more likely to be under-statement than exaggeration. Watson was always the man of action, and he rose to the occasion.
"Count me in, Holmes. I have nothing to do for a day or two."
"Your morals don't improve, Watson. You have added fibbing to your other vices. You bear every sign of the busy medical man, with calls on him every hour."
"Not such important ones. But can't you have this fellow arrested?"
"Yes, Watson, I could. That's what worries him so."
"But why don't you?"
"Because I don't know where the diamond is."
"Ah! Billy told me—the missing Crown jewel!"
"Yes, the great yellow Mazarin stone. I've cast my net and I have my fish. But I have not got the stone. What is the use of taking them? We can make the world a better place by laying them by the heels. But that is not what I am out for. It's the stone I want."