The Twister by Edgar Wallace

MR. ELK of Scotland Yard was the only detective known to fame who had ever permitted himself to be mysterious. And there was no circumstance about Mr. Elk's life that was more mysterious than the quality of lodgers who drifted to the house where be had his residence. Thieves, decayed noblemen, confidence men, and once a murderer, had slept under that interesting roof in the Gray's Inn Road. And now Tony Braid heard, dumbfounded, that a mysterious drunken somebody who knew all about Lulanga Oil Wells shared quarters with Mr. Elk. And just then Lulanga Oils was a subject which occupied his mind to the exclusion of all others.

To Ursula Frensham the topic of a possibly intoxicated authority upon Lulanga Oils was not especially fascinating. But this lank man, with the lined face and the twinkling eyes was a figure of romance.