On The Night Express by Fred M. White — Read

Jimmy Marrable was generally regarded by his host of friends and Bohemian acquaintances as the type of sunny, inconsequent individual who went through life with a smile on his lips and an easy heart so long as he had a shilling in his pocket and the prospect of enough to sustain him on the morrow. But, all the same, there was another side to Jimmy's character of which the public knew nothing. In the year or two preceding the war at a time when he was the only son of a prosperous father, it was his mood to drift about Europe with a wandering concert party and study men and things. But when the conflict began, Jimmy's knowledge of continental cities and his peculiar aptitude for picking up languages was properly appreciated by the English Secret Service, and only a few in the know were aware of what good work he had done for his country in connexion with Hugh Gaskell and one or two other adventurous spirits, who took their lives in their hands at the call of duty.

It was this side of Jimmy's character that came uppermost when he found himself in the seclusion of his bedroom on the evening after he had seen that green jade pocket book in the safe of that eccentric old gentleman under whose roof he lodged. It was a most remarkable discovery he had made and one that puzzled him exceedingly. He did not doubt for a moment that Wimpole was a perfectly harmless old gentleman, devoted only to his beloved bulbs and, therefore, the discovery that the missing pocket book was found amongst Wimpole's effects was something that caused Jimmy to sit up far into the night smoking countless cigarettes and trying to fit the pieces of the puzzle together. He went to bed presently, having abandoned the attempt for the moment and trusting to fortune to find a clue in some other direction.