Then, taking a newspaper from his pocket, he settled himself to read, apparently oblivious to his surroundings.
And yet as I watched I saw that over the top of his paper he was carefully taking in the general appearance of the place, and his eyes were keenly following the Russian's movements.

The latter shouted--in French--the order for the chop through the speaking-tube to the man Emilio, and then returning to his customer he spread out a napkin and placed a small cruet, with knife, fork, and bread before him.

But the customer seemed immersed in his paper, and never looked up until after the Russian's back was turned.

Then so deep was his interest in the place, and so keen those dark eyes of his, that the truth suddenly dawned upon me.

Mackenzie had telegraphed to Scotland Yard, and the customer sitting there was a detective who had come to investigate.