in other circumstances, anstruther would have been pleased with the turn of events. he knew now that smith, whom for so long he had been persecuting, was the rich lord barmouth. this, too, saved a deal of trouble; for instance, serena need not have been brought here at all. now anstruther would be able to blackmail barmouth for thousands, whereas he had been content with hundreds from the more humble smith. barmouth smiled, as he followed anstruther's train of thought. he was reading the other's mind like an open book.

"i know exactly what you are thinking about," he said. "you are not sighing for lost opportunities; you are going to make it all up in the future. still, i have puzzled you and, perhaps, frightened you a little. you are perfectly well aware why i have concealed my identity for so long. and you would give a great deal to know why i have so suddenly come out and met you in the open. on that point i have no intention of gratifying your curiosity. you may put your mask on again, and i will resume mine; but of one thing you may be certain. either as lord barmouth or as james smith, not one farthing more will you ever receive from me."

barmouth turned contemptuously away, and unlocked the door.

"now you can go your way, and i will go mine," he said. "i shall say nothing of this to lady barmouth; at least, not for the present. make the best of your evening's pleasure. it will be the last time you will ever be under my roof.

"with an irritated feeling of defeat anstruther stalked from the room, followed by lord barmouth, who lost no chance of hunting up jack and rigby. he told his interested listeners what had happened.

"i think you have acted wisely, lord barmouth," rigby said. "we are so hot upon the track of anstruther now that a day or two makes little difference. at the same time, i cannot quite see why anstruther should have come here in this mysterious way, when he might have accompanied claire quite openly."

jack was inspired with a sudden idea.

"it's all a question of alibi," he said. "we know perfectly well what an ingenious scheme anstruther has put up so that he may be what an irishman would call in two places at the same time. here is a magnificent opportunity of getting to the bottom of that mysterious music business."

"right you are," rigby cried. "it would be like flying in the face of providence to throw away such a chance. anstruther is here, and likely to remain, and so is serena. you may depend upon it that the other maid has gone to bed, so that we should have the house in panton square all to ourselves. you know the ropes better than i do, jack. can you tell us a good way of getting into the house without playing the burglar?"

jack thought a moment, then an inspiration came to him again; the thing was quite simple.

"we can walk into the place as if it belonged to us," he said. "when claire came away, anstruther told her that he should retire early. claire did not wish to keep the servants up unduly, so she took a latch-key with her."

"absolutely made for us," rigby exclaimed. "you go off to miss helmsley and borrow her latch-key, and we will get to the bottom of the whole mystery whilst anstruther is enjoying himself here."

jack came back presently with the latch-key in his possession. it was an easy matter to get out of the house without being observed; then a cab was called, and the two proceeded to jack's chambers, where they stripped off their fancy dresses hastily and assumed more civilized attire.

"i vote we take bates into this business," rigby suggested. "i've got a little idea of my own, which i will tell you about after we have been to panton square."

unfortunately the services of inspector bates were not available, for he had been called out on some business of importance, and was not expected back till the following morning.

"we shall have to go through it ourselves," jack said. "you will have a fine lot of copy for the planet a bit later on. i declare i am getting quite fascinated by my present occupation. shall we take a cab, or would it not be more safe for us to walk?"

panton square was reached at length, and no. 5 appeared to be in total darkness. as the friends had anticipated, serena's fellow servant had gone to bed, for neither at the front or back of the house was there so much as a glimmer of light to be seen. an application of the latch-key to the door proved quite successful, and a minute later the two friends were inside. they had not the slightest hesitation in putting up the lights, so that the passing police might infer that the occupants of the place had returned. not that he wanted to trouble much about anything but the study, seeing that it was there that the mysterious music always emanated.

it was an ordinary-looking room enough, the walls being entirely lined with books. there were books everywhere, not an inch of space being available for more. the ceiling was quite plain, and the closest search failed to disclose anything in the way of an apparatus by which the sounds of music could be conveyed from a distance into the study. jack looked round with a puzzled frown.

"all the same, it must come that way," he said. "i know perfectly well that one of padini's recitals came into this room as if it had been carried by some electrical means."

"a sort of telephone, i suppose," rigby said. "of course, we have all heard of the theatre-phone, but that theory would not work out in this case. with the dodge in question you have to plug both ears with a kind of receiver, and even then the music is only audible to those using the little receivers. in the present instance i understand that the whole room is flooded with melody, just as if the player were actually here."

"you've got it exactly," jack explained. "i have heard it myself, and so has claire; and both of us spotted the music as being in precisely the style of padini. hang me if i can see the slightest sign of how the thing is worked."

rigby said nothing; indeed, he was hardly listening. he was pacing round the room pulling armfuls of books out here and there, as if expecting to find some cunning device hidden behind the volumes. he stooped to pick up anstruther's violin case, which lay upon the floor. the case had been recently dropped, or some weight had fallen upon it, for the lid was cracked all across, and the hinges were broken. rigby gave a little cry as he threw back the lid.

"here's a discovery for you," he exclaimed. "anstruther's violin with the neck broken off. if you will look at it closely, you will see that it is covered with dust, and evidently has not been used for days. of course, it is just possible that anstruther possesses two violins----"

"i know as a matter of fact that he doesn't," jack said. "this is his cremona right enough. i have had it in my hands a hundred times."

"we are getting on," rigby laughed. "this room has been flooded with melody night after night, and yet we know for a fact that anstruther's violin has been absolutely useless."

"that does not help us to a solution of the problem," jack said. "but i have an idea. we shall never get to the truth through anstruther, but padini may help us. now it is very improbable that anstruther will be back under an hour. i'll stay here whilst you go off to the great metropolitan hotel and see padini. if you flatter him a bit, he will probably play to you. he will certainly do this in his own room, because professionals of mark never practice in public. what i am driving at is this: i feel quite certain that whatever padini plays to you, i shall hear in this room."

"excellent," rigby cried. "i will go at once."

late as it was, padini had not gone to bed; indeed, one of the corridor servants informed rigby that the violinist had been practicing on his violin for the past hour. without the slightest hesitation, rigby made his way into padini's room. the latter looked up with a puzzled air of surprise; evidently he had been taking a little more champagne than was good for him.

"i seem to know your face," he said. "of course you do," rigby said smoothly. "don't you remember me interviewing you for the planet? i happened to be in the hotel, and i thought i would look you up. i suppose it would be too much to ask you to play something to me? i am passionately fond of music, to say nothing of being a great admirer of yours. besides, i have a particular desire to hear you to-night."

padini looked up with just a shade of suspicion in his eyes. rigby felt that perhaps he was going a bit too far. he proceeded to flatter the artist to such an extent, that padini's suspicions were quickly lulled to rest. there was a half-empty bottle of champagne on the table, but rigby refused the proffered hospitality.

"no, thank you," he said. "i came to hear you play. i know it was a great liberty on my part and, if you like, you can turn me out at once; but i wish you would play something."

padini rose rather unsteadily, and reached for his violin. once his fingers grasped the neck of his instrument, he seemed to be himself again. rascal as the fellow was, there was no doubt of his great artistic qualities. he handled his bow with the air and grip of a master. he started some slow movement from one of beethoven's sonatas, and rigby lay back in his chair, giving himself up entirely to the delight of the moment.

it seemed, if padini once started, he would not know when to stop, for he played one piece after another, entirely forgetting that he had an audience. across rigby's brain there came floating the germ of a great idea. padini finished a brilliant passage, and the bow fell from his hands.

"there, my friend," he said breathlessly. "never have i played better than i have done to-night."

"you are indeed a master," rigby said, and he meant every word that he uttered. "an artist so great as yourself should be a composer also. have you published anything at all?"

the flattered artist replied that he had not published anything so far, but there were one or two little things which he had written in his spare time, and these he intended offering to some publisher who was prepared to pay a price for them.

"would you mind playing me one?" rigby asked. "i should prefer a piece that nobody has ever heard."

padini swept his bow across the strings, and proceeded to play a perfect little gem in a minor key. to a certain extent it reminded rigby of gounod's "ave maria," though its originality and breadth deprived it of any suggestion of plagiarism.

"perfect in its way," rigby said. "would you mind giving me the score? if you will, i can get a good price for it from the planet people. we are going to publish music at reasonable rates, and there is no reason why you should not have fifty guineas for yours."

padini declared that he quite shared rigby's opinion. he took a sheet of manuscript music from a drawer, and threw it carelessly across to his companion.

"there you are," he said. "make the best bargain you can for me. what? you are not going already?"

rigby muttered something to the effect that he had not yet finished his work at the office, and that he must tear himself away, much as he would like to have stayed to hear more of that beautiful music. a few minutes later rigby left the room. as he glanced back he saw that padini had fallen into his armchair again, and was already half asleep. rigby smiled to himself, wondering what padini would say if he knew the purpose to which the sheet of manuscript music would be devoted. he called a cab and hastened away in the direction of panton square, where he expected that jack would be still awaiting him. the lights were up at no. 5 just as they were when rigby had started for the great metropolitan hotel; but, all the same, he took the precaution of whistling softly, in case anything had gone wrong. the front door opened cautiously, and jack's head peeped out. a moment later, and rigby was inside.

"well?" he demanded impatiently. "anything happened?"

"a great deal," jack replied. "for half-an-hour everything was quiet, then that wonderful music started again. mind you, i haven't the remotest idea where it came from; i am just as much in the fog as ever. but it filled the room as if some great artist was invisible to me. i could recognize padini's touch. of course, i am assuming that you found him at home, and persuaded him to play to you. can i take that for granted?"

"it is exactly as you say," rigby explained. "please go on."

"then i will tell you what padini played. he started with the first part of 'the moonlight sonata.'"

rigby nodded and smiled. his smile broadened as jack proceeded to tick off the pieces of music just as they were played. "there was one, however, that i could not follow," he said. "it was that lovely little thing at the end. i am absolutely certain that it was an original piece of music."

rigby laughed as he produced the scrap of manuscript from his pocket. there was an expression of triumph on his face.

"original, and in my possession," he cried. "this scrap of paper contains the key of the whole situation."