Classicly

The Tempting of Tavernake is a mystery novel written by the English novelist Edward Phillips Oppenheim, who was one of the most successful thriller stories.

Excerpts:

They stood upon the roof of a London boarding-house in the neighborhood of Russell Square—one of those grim shelters, the refuge of Transatlantic curiosity and British penury. The girl—she represented the former race was leaning against the frail palisading, with gloomy expression and eyes set as though in fixed contemplation of the uninspiring panorama. The young man—unmistakably, uncompromisingly English—stood with his back to the chimney a few feet away, watching his companion.