here was proof positive enough to convict carrington of the crime which had been alleged against him. nor did jack doubt for a moment that anstruther was at the bottom of this daring and original scheme. the mere fact that there was another man in the cab with carrington was sufficient to prove this point, for nobody else was likely to accompany the bank manager on so delicate and private an errand. where the fatal mistake came in, was in carrington taking the bank of england notes from his own safe, and ignoring the fact that the official blue stamp was upon them.

as jack stepped into the street, he had pretty well made up his mind what to do. not for a moment did he believe that carrington had an accomplice amongst his own staff. jack reached the premises of the city and provincial at length, and asked to see mr. carrington. he was told that that gentleman had suddenly been called out on important business, and was not expected back to-day. but masefield was not in the least disappointed to hear this. there was nothing for it now, but to return to belgrave square, and tell the barmouths what had happened. he found lord barmouth in the drawing-room, where the blinds had been pulled down. lady barmouth had gone to an important function which she could not very well ignore, and had taken claire along with her. lord barmouth listened gravely to all that jack had to say.

"i am very much afraid that my wife will have to put up with the loss of her gems," he said. "no doubt they and many others are pledged with some great firm of pawnbrokers. the only consolation one has is the possibility of getting the stuff back by paying half its price over again. but matters cannot be allowed to rest here. carrington knows that he is at the end of his tether; consequently, that clever bogus burglary you heard discussed last night must take place this evening. what do you propose to do? in my present unfortunate condition i can't interfere. the only thing i can do is to leave it entirely in your hands."

jack went off presently to seek rigby, whom he found at his rooms. the latter looked up eagerly, for he could see from his friend's face that jack had a great deal to tell.

"there is one little thing that seems to stand in the way of our ultimate success," jack said, thoughtfully, "and that is as to lady barmouth's brother. i am afraid that he is in some way mixed up with this business--to his detriment, i mean. i should not care to do anything likely to cause additional pain to that estimable lady after all her great kindness."

rigby looked up in some bewilderment. apparently he did not quite understand the drift of jack's argument.

"i may be very dense," he said, "but i don't follow you. what can lady barmouth's brother have to do with it?"

"well, you must cast your memory back to the night of the great adventure, when lady barmouth played so courageous a part, and got us out of a serious difficulty. do you follow?"

"i think i do now," rigby said slowly. "oh, yes; it is all coming back to me. lady barmouth asked redgrave where her brother was, and redgrave replied that he knew nothing about the individual in question. but, my dear fellow, you have not proved to me yet that lady barmouth has a brother."

"now you are puzzling me," jack murmured.

"not at all. on the night i speak of, lady barmouth had to act on the spur of the moment. it was necessary to gag a bit to play for an opening. you are taking too much for granted. if lady barmouth has a brother, you will probably find that he has nothing to do with this matter. in any case, why worry about him to-night? we seem to have a big adventure before us so far as i can gather from what you have just told me. and if you are still in doubt, it will be quite an easy matter to see lady barmouth in the morning, and ascertain from her whether or not our proposed line of action is likely to do any harm. i don't suppose that lady barmouth knows or cares anything for redgrave, who appears to be a kind of sottish tool of anstruther's."

"quite right," jack agreed. "and now, come along and let us set the ball rolling again. i think that i have told you everything. and now we will go off without delay, and see seymour--the man i told you about, who was with me last night."

rigby assented to the suggestion eagerly enough, and together they set out in the direction of seymour's rooms. there was not much chance of the latter being out, seeing that he had his own cogent reasons for not facing the daylight, and surely enough it turned out as masefield had expected.

seymour was dawdling over his tea with a cigarette and a french novel, a bored expression on his face. that face, however, became eager and animated as jack came in and introduced rigby to his host.

"things are beginning to move rapidly then," seymour exclaimed. "your face speaks of action, mr. masefield. is it about carrington? you have discovered something fresh."

"i think i have discovered pretty well everything," jack replied. "i have managed to force that fellow's hand, just as rigby suggested i should. he has consulted anstruther, as we knew he would; and a pretty scheme for gaining time they evolved between them. but perhaps i had better tell you everything."

seymour pitched his french novel aside, and his intelligent face beamed with animation. the story was told at length, and seymour warmly congratulated the speaker upon his astuteness and intelligence.

"i quite agree with you," seymour said. "if carrington's good name is to be saved at all, that bogus burglary must take place to-night."

"by the way!" jack exclaimed. "there is one thing i quite forgot to tell you--that is the little adventure i had last night at the great metropolitan hotel. i found an invalid gentleman there--or, at least, he found me--who seems to know all about anstruther and his movements. he knows you, too; indeed, he seemed to be overjoyed that you are in england. he had some hesitation in mentioning his own name, but he said that if i gave you a certain ring which is now in my possession, you would understand everything."

jack laid the ring upon the table, and seymour pounced upon it like a hawk would pounce upon a mouse. a grim smile played about the corners of his mouth, but, self-controlled as he was, he could not altogether hide his feelings.

"tell me all that happened with my friend last night," he asked. "it has an important bearing on this case."

jack proceeded to explain, seymour listening in an attitude of rigid attention.

"this is the best news i have heard for some time," he said. "you can make your mind quite easy on one thing--anstruther has nearly shot his bolt. after to-morrow i will get you to arrange a meeting between myself and my old friend at the great metropolitan hotel. meanwhile, there is much to be done. it is quite certain that great things are going to happen at the city and provincial bank to-night. i think we shall have a pleasant little surprise for anstruther and co."

seymour rose, and took a roll of tissue paper from a small safe in the corner of the room.

"these are the plans of the city and provincial bank," he explained--"the plans that came so luckily into our hands last night. i have studied them very carefully. as a matter of fact, i did not come straight home last night, but passed the hours till nearly daylight prowling about the bank. without the plans, my scheme would be quite futile; but i think now that i have the whole thing very prettily mapped out. just come and look at this with me. it is really very simple."

as seymour had said, the plan was simplicity itself. it not only gave a very intelligent idea of the situation of the vaults and strong rooms, but also the back premises and the lanes behind were clearly marked.

"now i want you to follow this very carefully," seymour went on. "we can ignore the front of the building altogether, because that faces on gresham street. here the police pass the same premises every three minutes, so that nobody could force an entrance that way, not even the would-be burglars with their keys. but if you look at the rear of the place, you will see that there is a small alley leading out of farringdon lane, and this alley ends by a kind of back entry into the bank which is used by the caretaker. i have ascertained that there are two night watchmen, so that there is not much danger of trouble. by the side of this door is a small window, the latch of which i have ascertained to be defective.

"i suppose no one has ever troubled to see to this, for the simple reason that admission to the bank premises by no means implies getting to that part of the building which is devoted to business purposes. not that we particularly want to penetrate very far, because it is our scheme to watch what is going on, so that we may be able to confront the scoundrels when the proper time comes. a careful examination of these plans shows me that we shall be able to get as far as the bank proper, which means the counting house, and from thence down the steps to the vaults where the strong rooms are situated."

"have you got keys of all these?" jack asked.

"there will be no necessity for us to provide keys," seymour chuckled. "you see, anstruther and co. will be bound to enter the bank from the back premises. by learning this plan off by heart, we come to know exactly which way they will get to the vaults. of course, they will come provided with keys--carrington will see to that. all we have to do is to hide under a counter or something of that sort, and wait till our friends come along. naturally, they will not dream that any one is on the premises besides themselves. as to the rest, you must leave that to me and fortune. you had better stay here and dine, and we can set out for the city about eleven o'clock."

it seemed to both rigby and masefield that it would be impossible to improve upon this plan. they dined comfortably and discreetly, and it was somewhere about half-past eleven when they turned their faces in the direction of the city. no one appeared to notice them, for they walked rapidly along, with the air of men who had business before them, and the police appeared to be few and far between. they came at length to the little alley at the rear of the bank, and here it behoved them to be cautious. they waited till the beat of the policeman's feet died away down the lane, and then they darted down the dark entry. seymour produced a tiny electric torch from his pocket.

"there is the window," he whispered. "i am going to get on your shoulders, mr. rigby. once i am through, i can pull you others up. there is no sort of danger."

"oh, but there is," jack protested. "you have utterly forgotten one thing--did you not tell me there were two night watchmen on the premises?"

seymour chuckled, and was understood to say that they would find anstruther had removed that difficulty for them. seymour seemed so sure of his ground that jack waived his protest. a minute later seymour was through the window, and the others followed swiftly. rather recklessly, or so it seemed to jack, seymour waved his electric torch so as to form a line of light in front. he smiled grimly as he pointed to two unconscious figures reclining back as if hopelessly drunk in a pair of deep armchairs. they came so suddenly upon the unfortunate victims that jack fairly started. but so far as seymour was concerned, he had appeared to have expected something of the kind. he again chuckled hoarsely.

"what did i tell you?" he asked. "did i not say that anstruther and co. would very kindly get the caretakers out of the way for us? you see the caretakers would have been just as much of a nuisance to them as they are to us. they have been carefully hocussed, and not until an alarm is given in the morning will they be in a position to say anything."

the last danger being apparently removed, the trio proceeded to make their way to the bank premises proper, and there made themselves as comfortable as possible under one of the counters in the counting house. it was very quiet there, so quiet that they could hear the tramping footsteps of the police outside, and the singing of some belated reveler. they lay there till they heard the great clock of st. paul's strike the hour of one. there was a sound then of heavy footsteps tramping along the corridor, and presently a great blaze of light filled the counting house. it was perfectly safe, for the heavy iron shutters excluded every ray from the outside. seymour rose cautiously, then ducked his head again.

"just look," he whispered. "make sure who it is."

rigby raised his head cautiously, too. the light fell full upon the face of the intruder--the white, stern face of anstruther.

"now for it," seymour whispered; "the play is about to begin."