Henry Leverage, The white cipher (1919)
“ The romance of all underworld activity on the Continent and in England was bound up in the Yard. Its long arm could reach down a blind alley in Paris and snatch a man to the light of justice. It could lift a fleeing suspect from the deck of a ship at sea. It stopped at nothing!Fay suspected a well-baited trap of the superior order as he followed MacKeenon through a dim-lighted hallway. He gripped his palms as they waited in the gloom for a door to be unlocked by the servant who had answered the inspector’s knock of four taps and then five. ”
