"Then I received information that Ivan and a man my informant took for Goldenburg had been seen at Victoria Station on the night of the murder. I managed to find Ivan and, by a threat, got a partly formed opinion confirmed. He knew that the murdered man was not Mr. Grell. I took from him the pearls that were to have formed a wedding present, and let him go after taking his finger-prints. My idea was to have him watched, for I felt confident that he was in touch with his master--whom I believed to be the murderer. "But it was not enough to follow one line. We used the fact of the striking similarity of Grell and Goldenburg to advertise for the former under the name of the latter. The mere fact of throwing the description broadcast, was calculated to make any attempt to escape more difficult. Meanwhile, we were making inquiries about every one concerned in the case by co-operation of foreign police-forces, and particularly with the help of Pinkerton's agency in the United States. It was all organisation, you see--the individual counted for little. "The first attempt to communicate with Fairfield failed, not through the working of any miracle on our part, but by patient watching. I stole a note from Fairfield, which gave us something to act upon, in the East End. Remember, the immediate object of our search was Robert Grell--not necessarily for the murderer. Do you follow?" "I think I do," answered Grell. "You wanted, at least, an explanation from me." "Precisely. Well, on top of that, we got a typewritten letter, informing us of the kidnapping of Waverley. That letter was important, for its contents showed that we were up against people who were absolutely reckless. We were able to trace, too, a typewriting machine as having been sold recently to a man named Israel, in Grave Street, There were finger-prints on the letter, and they corresponded to those on the dagger. As a matter of fact, I recently found out that the letter had been written on paper given by you. You had torn a half-sheet from an old letter, and I can only presume it was one that had been written to you by Lady Eileen Meredith. For they were her finger-prints. "We paid a surprise visit to Grave Street, and, although we were unable to lay our hands on any one of much importance to the investigation, we hit on the cipher with which it was intended to communicate with your friends. Now, we had already, as you know, taken every precaution to stop supplies. It was obvious that, sooner or later, money would be wanted, and we rigorously watched the persons who were likely to be applied to. Up to this point, circumstantial evidence pointed clearly to you"--he nodded towards Grell--"as the murderer.