at eight-thirty mr. thurlow considered that his continued refusal to have dinner served was making much of what he was determined to think was a small affair. at eight-forty he said that he had eaten all he required, and he telephoned to scotland yard again. this time, he was not told that there was no news. kindell answered him, and his anxiety was evident in his voice. "there's one thing turned up, but you can't call it good, and it isn't easy to guess what the explanation can be. we only heard it a few minutes ago, and i was just going to ring you. the taxi's been found, but the driver's missing."

"you mean the car's been abandoned?"

"not exactly. or at least not as though it were done in a hurry. it's standing on a cab rank off holborn, but there's no-one in charge. it was reported by another driver, who said it was obstructing the rank."

"you've no clue to what happened?"

"we're fetching it in now."

"there's no news of rene?"

"nothing here. i hoped she might have got home."

"well, she hasn't. i can't understand how - - "

"superintendent allenby wishes me to assure you that everything possible's being done."

"i can't agree about that. . . . i'm coming over now."

the ambassador heard kindell say, "he says he's coming here now," and then, a moment later, "superintendent allenby says he'll be glad to see you."

"will he? i hope he'll have some better news for me than he's got now."

mr. thurlow rang off without giving time for reply. he ordered a car, and then turned to the drawer which he had opened before. but this time the gun he handled was not laid down, but slipped into a hip-pocket which readily adapted itself to a shape it had known before.

he gave a brief instruction that he was to be rung up instantly at scotland yard if irene should return, and it was no more than a few minutes later that he was in the presence of superintendent allenby, and found that he had met a man whose efficient unhurried urbanity even his anxious impatience could not disturb. being one who was not only efficient himself, but who could recognize that quality in others, he was also quick to recognize that everything possible was being done, and his manner changed.

"i am glad you have come," the superintendent began "because i should like you to know what steps we have already taken, and to hear any suggestions for further action which your experience and knowledge of those concerned may suggest.

"it is difficult, on our present information, to decide with certainty what has occurred, but there are certain indications which limit the scope of our enquiries, and should be of material assistance in solving the problem, even although we are dealing with particularly astute and unscrupulous men, who have the assistance that money gives.

"i should tell you first that we are proceeding on the assumption that kindell really did make no mistake in the number of the car, and we are at least equally certain that the one that legitimate]y bears that number was standing outside the lyric theatre during the time that he was following a similar one in the mostyn road.

"you will readily see the implications of - - "

he broke off as a clerk entered the room and laid a sheet of typed foolscap before him. "these are the particulars for which you asked, sir."

superintendent allenby's glance went rapidly down the page. his pencil ticked three of the list of names which it showed. "they must all be followed up," he said, "and without delay. tell chief inspector rolls that the three i have marked are worth special attention."

he explained, as the clerk withdrew "that was a list of all the new starmar cars of that pattern, size, and quality which have been sold during the last year. we are probing the possibility that someone has deliberately used a fake number-plate identical with that of miss courtney, either habitually, or more probably, on particular occasions when occupied in illegal traffic. it is a device which shows the elaborate trickery of the men with whom we are concerned, and which might have caused more confusion and uncertainty than it has."

"i am surprised that you have been able to obtain the list so quickly."

"we had the secretary of the starmar company on the telephone. we contacted him at the plaza an hour ago. he was good enough to ring up a managing clerk who lives within two miles of their nottingham offices, and to arrange for him to go there and 'phone us the required particulars. they have come through half an hour earlier than i could reasonably have expected. a member of the starmar staff would doubtless have a fast car! . . . you may be sure," he added, "that we should allow no time to be lost in view of miss thurlow being concerned; though i should not wish you to think that we are seriously concerned for her safety. as i said before, the criminals with whom we are

dealing are as astute as they are unscrupulous, and that astuteness would make them particularly careful not to interfere with anyone in miss thurlow's position."

"if she isn't home in the next hour, you can reckon she's being detained somewhere by force, and if that isn't interference - "

"i shall be inclined to agree with you about that, particularly as there is good reason to believe that the car cannot have gone far. of course, i cannot vouch for the vigilance or for the intelligence of every member of the constabulary force of half a dozen counties round london, but unless there has been a remissness somewhere such as there is no reason to expect, that car did not get away for more than fifteen miles, and probably ran under cover somewhere very much nearer.

"this is rendered more probable - indeed, almost certain - by the fact that peller's car has been found so short a distance away, and - - "

"peller being the taxi-driver?"

"yes."

"you don't think he could have been in collusion with them?"

"the circumstances make it improbable; apart from which inspector barclay, who deals with these drivers, says that he has known him for twenty years, and has confidence that he is a straight man."

"you're certainly picking up the threads. but doesn't the fact that he has disappeared, being a man of that character, make the whole thing look a lot worse?"

"i have no wish to minimize it. and i am disposed, as i have said already, to agree that, if miss thurlow is not back very soon, the probability that she is being detained against her will must be recognized. what i meant was that they will be very careful not to treat her with any disrespect. it is more probable that she would merely be prevented from communicating with us long enough for them to get away, or to remove incriminating evidence."

"and the driver also?"

"it is hard to reconstruct what has occurred from the material at present available. he may have had to choose between protecting his passenger and abandoning his car. it was evidently important to move it from wherever it was, which must therefore almost certainly have been near some premises occupied by members of the gang - presumably where the grey car is hidden which it would have given away. the fact that it was not merely driven to a misleading distance, and abandoned there, but put on to a cab rank, suggests that it was considered important to delay its discovery as long as possible. it might have stood there for many hours without being reported to us. and that supports my suggestion that the detention of both miss thurlow and the driver - if that should be actually occurring - may be of a temporary character. but it is our business to make that time too short for their escape, which we may still hope to do."

having said this, the superintendent switched his desk telephone to enquire as to whether peller's car had been brought in.

so it had, but he was to gain no satisfaction from that. it was in good order. there was no slightest sign of any struggle having occurred, or any abnormality of any kind. it was just an empty car.

thurlow said abruptly, "i suppose that fellow blinkwell's at the bottom of this?"

the superintendent replied with caution. he did not forget that he had received direct instructions from the home secretary on the telephone half an hour earlier that he must keep the united states ambassador clear of further complications at almost any cost. he said "there is a grave suspicion of that. he is being closely watched. he will be unable to go anywhere, or to write or telephone, unobserved, as long as this matter remains unexplained. but it may be very important that he should not know that he is suspected by us."

"learnt anything so far?"

"less than an hour ago, there was a telephone conversation between a man at a call-box and someone who spoke from blinkwell's laboratories in the name of one of his staff, but who may have been blinkwell himself. if it were so the conversation was intended to mislead anyone who should listen-in, but it would appear that something had been done at which blinkwell was surprised and annoyed, and that he told the man who spoke to him that he must get out of his own mess in his own way."

"you'll have thought of sending someone to question him?"

"it would almost certainly be useless. he would deny everything. professor blinkwell is a very clever man. it would be we who would have given ourselves away."

"you wouldn't think to threaten him with a bullet in a nasty spot unless he should come clean?"

"no. we are not encouraged to those methods. public opinion is troublesome in this country."

"but if i were to do it for you, it might give you a leg up?"

superintendent allenby knew that he would be blamed if he should permit that which he had yet no legal power to prevent. he judged also that mr. thurlow was not a man who would be easy to turn, especially where his daughter's safety was so nearly concerned. he showed his fitness for the position he held when he answered readily: "yes. that might be worth trying. your trouble would be that you couldn't carry out the threat if the bluff should fail. . . . certainly not on anything we know now." he went on hastily to the suggestion to which he had been leading, seeing an expression on his visitor's face which he would prefer not to hear put into words: "but i can make a better suggestion. we can send kindell. it would be natural for him to call, and he can show his hand, more or less, as the occasion requires."

mr. thurlow did not reject the proposal, but he did hot look pleased. he would far rather have gone himself. he was impatient for action, and he had some confidence in his powers of persuasion, supported by that which his pocket held. yet he was not insensible to the difficulty which had been suggested to him. he could threaten blinkwell with a bullet if he should refuse to talk, but what if he should call his bluff? if he should be obstinate, or even unable to give the information required?

mr. thurlow saw that the superintendent was right. he would be unable even to give the professor an advisory bullet in a non-vital spot. even had he been no more than a private citizen of the united states, his difficulty would still have been that, however strong his suspicion, he was not sure. as it was, with the responsibility of his official position upon his mind - no, it could not be done. not even for irene's safety. they must think of something better than that.

yet he was slow to approve the suggestion that kindell should go. he was still somewhat dubious of what his relations with professor blinkwell - his feelings towards myra - might be. the doubt was slight, but it was still there. and there was also that of his ability to handle the situation. "you think," he asked, "that kindell could pull it off better than i?"

"kindell is one of our most trusted agents. he has already established such relations with professor blinkwell - and with his daughter - that it will be natural for him to call to let them know that he has been released by the french police."

"very well. the sooner he gets started the better."

"yes. for every reason. a midnight call would require more explanation than it would be easy to give."

as the superintendent said this, he 'phoned for kindell, who had been waiting impatiently in an adjoining room to hear the result of this interview. there was a brief discussion of how it would be best to act under the varying circumstances which might confront him, and then kindell, avoiding the use of an official car, set out on foot, and stopped the first taxi that cruised past him with a lifted flag.

as he was on the way, he considered that it was already late, and that the professor might well decline to see him at such an hour. what should he do then? how should he force an interview which he would be unwilling to defer?

his plan was ready when he arrived at his destination, but it was not required, for professor blinkwell was as anxious for information as he. he said that he would see mr. kindell.