The Hunchback of Westminster by William le Queux

Just at that moment a man's form emerged from the darkness on the opposite side of the street, and a familiar voice called to me in a loud but commanding whisper: "Glynn! Glynn! Is that you? You're here late, aren't you? " I wheeled round suddenly, and recognised the speaker. It was Detective-Inspector Naylor of Scotland Yard, with whom in times past I had been engaged in several joint investigations in which society and crime played parts of equally unpleasant prominence.

"Hullo! " I said, puzzled to know what to say, and still bewildered by the unexpected climax to my last interview. "What the deuce are you doing here at this ungodly time of night? Got something good professionally on, eh?"