action, relying partly on violence, the professional spy has every facility to fabricate the very facts themselves, and will spread the double evil of emulation in one direction, and of panic, hasty legislation, unreflecting hate, in the other. However, this is an imperfect world--'

The deep-voiced Presence on the hearthrug, motionless, with big elbows stuck out, said hastily:

`Be lucid, please.'

`Yes, Sir Ethelred - An imperfect world. Therefore directly the character of this affair suggested itself to me, I thought it should be dealt with with special secrecy, and ventured to come over here.'

`That's right,' approved the great Personage, glancing down complacently over his double chin. `I am glad there's somebody over at your shop who thinks that the Secretary of State may be trusted now and then.'

The Assistant Commissioner had an amused smile. `I was really thinking that it might be better at this stage for Heat to be replaced by--'

`What! Heat? An ass - eh?' exclaimed the great man with distinct animosity.

`Not at all. Pray, Sir Ethelred, don't put that unjust interpretation on my remarks.'

`Then what? Too clever by half?'

`Neither - at least not as a rule. All the grounds of my surmises I have from him. The only thing I've discovered by myself is that he has been making use of that man privately. Who could blame him? He's an old police hand. He told me virtually that he must have tools to work with. It occurred to me that this tool should be surrendered to the Special Crimes division as a whole, instead of remaining the private property of Chief Inspector Heat. I extended my conception of our departmental duties to the suppression of the secret agent. But Chief Inspector Heat is an old departmental hand. He would accuse me of perverting its morality and attacking its efficiency. He would define it bitterly as protection extended to the criminal class of revolutionists. It would mean just that to him.'

`Yes. But what do you mean?'

`I mean to say, first, that there's but poor comfort in being able to declare that any given act of violence - damaging property or destroying life - is not the work of anarchism at all, but of something else altogether - some species of authorized scoundrelism. This, I fancy, is much more frequent than we suppose. Next, it's obvious that the existence of these people in the pay of foreign governments destroys in a measure the efficiency of our supervision. A spy of that sort can afford to be more reckless than the most reckless of conspirators. His occupation is free from all restraint. He's without as much faith as is necessary for complete negation, and without that much law as is implied in lawlessness. Thirdly, the existence of these spies amongst the revolutionary groups, which we are reproached for harbouring here, does away with all certitude. You have received a reassuring statement from Chief Inspector Heat some time ago. It was by no means groundless - and yet this episode happens. I call it an episode, because this affair, I make bold to say, is episodic; it is no part of any general scheme, however wild. The very peculiarities which surprise and perplex Chief Inspector Heat establish its character in my eyes. I am keeping clear of details, Sir Ethelred.'

The Personage on the hearthrug had been listening with profound attention.

`Just so. Be as concise as you can.'

The Assistant Commissioner intimated by an earnest, deferential gesture that he was anxious to be concise.