His wisdom was of an official kind, or else he might have reflected upon a matter not of theory but of experience that in the close-woven stuff of relations between conspirator and police there occur unexpected solutions of continuity, sudden holes in space and time.

A given anarchist may be watched inch by inch and minute by minute, but a moment always comes when somehow all sight and touch of him are lost for a few hours, during which something (generally an explosion) more or less deplorable does happen.

But the high official, carried away by his sense of the fitness of things, had smiled, and now the recollection of that smile was very annoying to Chief Inspector Heat, principal expert in anarchist procedure.
This was not the only circumstance whose recollection depressed the usual serenity of the eminent specialist.

There was another dating back only to that very morning.

The thought that when called urgently to his Assistant Commissioner's private room he had been unable to conceal his astonishment was distinctly vexing.