The Uttermost Farthing by Marie Belloc Lowndes

Once a year the newspapers of each great capital publish, among other statistics, a record of the disappearances which have occurred in their midst during the preceding twelve months. These disappearances are not counted by tens or by hundreds, but by thousands; and what is true of every great city is in a very special sense true of Paris, the human Cloaca Maxima of the world. There, the sudden vanishing, the obliteration as it were, of a human being -- especially of a foreigner -- arouses comparatively little surprise or interest among those whose weary duty it is to try and find what has become of the lost one.

To Madame de Lera, -- even to Tom Pargeter, -- the beginning of what was to be so singular and perplexing a quest had about it something awe-inspiring and absorbing. So it was that during the few minutes which elapsed between their leaving the Avenue du Bois de Bologne and their reaching the ancient building where the Paris Police still has its headquarters, not a word was spoken by either of the two ill-assorted companions who sat together in the rear of the car, for Vanderlyn, the only one of the three who knew where the Prefecture of Police is situated, had been placed next to the chauffeur in order that he might direct him as to the way thither.