The Lone Wolf by Louis Joseph Vance

His return to Troyon's, whereas an enterprise which Lanyard had been contemplating for several years -- in fact, ever since the death of Bourke -- came to pass at length almost purely as an affair of impulse.

He had come through from London by the afternoon service -- via Boulogne -- travelling light, with nothing but a brace of handbags and his life in his hands. Two coups to his credit since the previous midnight had made the shift advisable, though only one of them, the later, rendered it urgent.