WHEN PROFESSOR BLINKWELL relayed the message to Snacklit concerning the dog with the bad ear, he was - need it be said? - concerned for himself only. He had already decided that the dog-killer's use was done, and that his liquidation must be quietly arranged so soon as this annoying episode should be ended in a way which past experiences gave him reason for feeling confident that he could contrive.

Neither had he come to a final decision as to what it would be best to do about the girl whom Snacklit had so foolishly guided and admitted to his own premises, after he had allowed her to identify him as the man who had called to collect the case of illicit drugs.

But he saw the necessity of restraining Snacklit from irrevocable action before his own mind should be made up. To defer it might increase Snacklit's risk, if the car should be traced to his door, but Professor Blinkwell was not equally clear that it would increase his own, which was his single concern.

He had a doubtful hope that the police would accept the offer which he had made, in view of the nationality and position of the missing girl, and he saw advantages to himself if he should appear as one who could find and rescue her when they had been foiled. It was not a tale for their own credit, that they would wish to have widely known. . . . And there would be her father's gratitude. Something could surely be made of that.

But he saw that it would not be an easy bargain to make or define, and he did not expect to get an immediate reply. Superintendent Allenby's judgment had been sound when he had said that, while the reply was delayed, the Professor would be likely to use his influence in the right way.

That on which Allenby did not calculate, and which was even more surprising to the Professor than it would have been to himself, was that the Professor would find that his authority was not enough. Yet such was the fact.

Snacklit hurried to the telephone in response to the urgent call he received, and was instructed in cryptic words, but such as he could not possibly misunderstand, that Miss Thurlow must be treated with every possible consideration until further orders should be received. Snacklit, worried though he would have been, in view of the disappearance of a taxi-driver concerning which he would surely have to face a hostile investigation if Irene should be released, would probably have done what he was told, but for what he knew that Irene had seen.

Unfortunately, to narrate this episode was, in spite of its ingenious complexity, beyond the resources of the code he used. He felt that the occurrence itself, joined to his inability to report it, justified some independence of action. Without possibility of such explanation as might, even to Professor Blinkwell's merciless discipline, have gone some way toward condoning his insubordination, he made it clear that he could not undertake to comply with the instructions he had received.

He was curter in this than he might otherwise have been because he was uneasy at having left Irene, which he had not intended to do until he had satisfied himself that she had told him all that she could and he had disposed of her in a final manner, for which his plans had been made.

But Professor Blinkwell received his message with a mingling of astonishment and anger which was not free from an under-current of fear. A gang which operates outside the law, which handles large sums of money, and the members of which must depend upon a common loyalty for their own protection, is only held together by ruthless discipline, such as Professor Blinkwell had shown himself able and resolute to enforce. No one knew these facts better than Snacklit, who had been executioner of more than one on whom the Professor had passed sentence of death which might be unknown to the victim until he found himself in the hands of those by whom he would be bound, drugged, and thrust into the asphyxiating chamber, for the existence of which there was such an excellent pretext - or perhaps even thrown into the incinerator without that preliminary, if there should be occasion for haste. . . . Was there not a reason for that incinerator also which all nice-minded people would approve? Who would wish to see a daily heap of dead dogs of all shapes and sizes shovelled into a cart in the open street?

To the Professor's mind the fact that Snacklit should venture upon an insubordinate attitude in the moment of common peril had a note of ominous warning beyond anything he had encountered during this most vexatious episode of his career ............