The Professor had already stopped, with a ready half turn which brought his shoulders very near the other wall. His right hand fell lightly on the back of the outcast couch, the left remained purposefully plunged deep in the trouser pocket, and the roundness of the heavy rimmed spectacles imparted an owlish character to his moody, unperturbed face.

It was like a meeting in a side corridor of a mansion full of life. The stalwart man was buttoned up in a dark overcoat, and carried an umbrella. His hat, tilted back, uncovered a good deal of forehead, which appeared very white in the dusk. In the dark patches of the orbits the eyeballs glimmered piercingly. Long, drooping moustaches, the colour of ripe corn, framed with their points the square block of his shaved chin.

`I am not looking for you,' he said, curtly.

The Professor did not stir an inch. The blended noises of the enormous town sank down to an inarticulate low murmur. Chief Inspector Heat of the Special Crime Department changed his tone.

`Not in a hurry to get home?' he asked, with mocking simplicity.

The unwholesome-looking little moral agent of destruction exulted silently in the possession of personal prestige, keeping in check this man armed with the defensive mandate of a menaced society. More fortunate than Caligula, who wished that the Roman Senate had only one head for the better satisfaction of his cruel lust, he beheld in that one man all the forces he had set at defiance: the force of law, property, oppression, and injustice. He beheld all his enemies and fearlessly confronted them all in a supreme satisfaction of his vanity. They stood perplexed before him as if before a dreadful portent. He gloated inwardly over the chance of this meeting affirming his superiority over all the multitude of mankind.

It was in reality a chance meeting. Chief Inspector Heat had had a disagreeably busy day since his department received the first telegram from Greenwich a little before eleven in the morning. First of all, the fact of the outrage being attempted less than a week after he had assured a high official that no outbreak of anarchist activity was to be apprehended was sufficiently annoying. If he ever thought himself safe in making a statement, it was then. He had made that statement with infinite satisfaction to himself, because it was clear that the high official desired greatly to hear that very thing. He had affirmed that nothing of the sort could even be thought of without the department being aware of it within twenty-four hours; and he had spoken thus in his consciousness of being the great expert of his department. He had gone even so far as to utter words which true wisdom would have kept back. But Chief Inspector Heat was not very wise - at least not truly so. True wisdom, which is not certain of anything in this world of contradictions, would have prevented him from attaining his present position. It would have alarmed his superiors, and done away with his chances of promotion. His promotion had been very rapid.

`There isn't one of them, sir, that we couldn't lay our hands on at any time of night or day. We know what each of them is doing hour by hour,' he had declared. And the high official had deigned to smile. This was so obviously the right thing to say for an officer of Chief Inspector Heat's reputation that it was perfectly delightful. The high official believed the declaration, which chimed in with his idea of the fitness of things. 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 the 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 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