"Oh, there was no fear of my saying anything about the commission you gave me. I did not even leave my name." I breathed more freely. "I went to see you because I had something to tell you which I thought you would like to know immediately."

"What is it?"

"Mr. Nisbet is in London," replied Mr. Dickson.

CHAPTER XX.

[DR. COOPER.]

I caught my breath. There was nothing strange in the information; for all I knew Mr. Nisbet might have been in London for years, as ignorant of my existence as, until lately, I had been of his; but the accidental discoveries of the last few hours seemed to me to be pregnant with important possibilities.

"I am glad you have lost no time in telling me," I said. "How did you discover it?"

"Almost by accident. I have a partner, whose methods are of the quiet order, I being the active worker in our business, and it is he who made the discovery--almost by accident, as I have said. Nisbet is not a very uncommon name, but tack Oliver to it, and it becomes exceptional. Yesterday there arrived from the Continent a gentleman bearing those two names, and he is now at the Hôtel Métropole."

This destroyed the hypothesis that Mr. Nisbet had been a constant resident in London since my introduction to the skeleton cat.

"From what part of the Continent?" I inquired.