malcolm grey sat himself down to wait grimly and patiently for tanza. from his position on the lawn he commanded a view of the front of the house. he had the satisfaction of knowing that rent was safe and that he could not leave without being seen. in one of the rooms at the top of the house the light flickered from time to time, so that grey had a fair idea of where rent was and what he was doing. the better part of half an hour elapsed before tanza appeared on the scene. grey hailed him in a whisper, and he crept noiselessly across the grass. for once he appeared to be curious.
"what is on foot now?" he demanded. "why did you send for me in so mysterious a fashion? why is there a light at the top of the house? is the problem solved?"
"to all practical purposes it is," grey replied. "i know what took place, and why. but precisely how the mischief was brought about i cannot say. possibly before daylight the thing may be explained. but that depends upon luck. at any rate, i am going to take you into my confidence and tell you what i have discovered."
"i am glad to hear that," tanza murmured.
tanza inclined his head to listen, and for the next quarter of an hour followed grey with the most careful attention. he was more interested than perhaps he had ever been before in his life. the strangely tangled web which grey was unfolding was the most complicated of all the affairs in which he had ever been engaged.
"wonderful," he murmured. "really, a work of art. perhaps it is rather cold-blooded of me to regard these puzzles in the way of a recreation. but there is a peculiar horror about this affair which has rarely been equalled. so that's the way the thing was done, eh? well, i suppose i must leave the matter in your hands. what do you propose to do next? but, by the way, you have not yet told me who is in the bedroom overhead."
"you will be surprised when i tell you," grey murmured. "the intruder is no other than arnold rent."
an exclamation of genuine surprise broke from tanza's lips.
"is that really a fact?" he demanded. "but what brings him here? what has he come after?"
"ah, that i can only conjecture. i don't think my theory is far wrong. although arnold rent is the son of a rich woman, he has by no means the command of unlimited money. mrs. rent is rather simple in her ideas and inclined to be somewhat of a puritan. she is quite capable of leaving her money elsewhere if she thinks her son will waste it. therefore, it has been a necessity on rent's part that his mother should be deceived as to his mode of life. to put it plainly, he is more or less afraid of her. and when a man lives in a smart set, and has no control over his expenditure, he is bound sooner or later to find himself in difficulties. that is the matter with rent. he did not know which way to turn for money. he did not dare to go to his mother and ask her to set him on his feet again. therefore he hits upon another plan. he makes violent love to bark's sister hortense with a view to securing her mistress's diamonds. at first i don't believe that rent cared for mrs. charlock at all. what he meant to do was to get hold of her jewels, but when he came to know the woman intimately she fascinated him to such an extent that he lost his head. he was prepared to sacrifice everything for her sake. witness that mad idea of his taking mrs. charlock to stay with his mother. i give the fellow credit for honesty in that respect. i believe his affection for mrs. charlock was absolutely pure and good—perhaps the only disinterested impulse he ever had in his life. meanwhile, he had talked hortense over and between them they laid hands upon mrs. charlock's jewels. you will ask what became of the jewels. they were hidden in a place of safety, so that they might be available when they were wanted."
"that sounds logical," tanza said. "is it part of the problem to find the jewels, or do you know where they are?"
"i know where they are," was the unexpected reply. "they are within a stone's throw of us."
the little italian whistled softly.
"oh," he said, "i shall have to hand my mantle over to you, i see. but hadn't we better secure the plunder while we have the chance? it would be folly to miss the opportunity."
"oh, the gems are safe enough," grey said, with a grim chuckle. "you can almost touch them with your hands. and yet they are as safe as the crown jewels in the tower of london. indeed, they are safer, seeing that an attempt on the national regalia would only end in imprisonment, while a determined attack upon mrs. charlock's gems would end in sudden death. i won't gratify your curiosity yet. i have told you enough for the present, and the truth, too. the first hand that rests upon that jewel case will be the hand of a corpse in the twinkling of an eye. in a day or two, perhaps, it may be safe to rifle the hiding-place. but not yet, not yet."
grey spoke with a thrill in his voice that had something of horror in it. tanza had seen too many mysteries in his time to express anything in the way of incredulity. on the contrary, he nodded his head solemnly.
"does anybody else know?" he asked.
"anybody besides arnold rent, you mean?" grey replied. "well, yes, one other person knows, and that is ephraim bark. his information came to him from his sister, who wrote and told him all about the affair when she discovered that she had been made a tool of by rent and that he did not care two straws for her. we shall know presently how rent managed to silence that jealous woman's tongue and leave the field clear for himself."
"you mean to say," tanza began, "that arnold rent——"
"my dear fellow, i mean to say nothing. i shall have a repulsive enough task later when i am compelled to speak plainly. meanwhile, i have told you pretty well all there is to know. we had better go up and see what arnold rent is doing. you will not be surprised to hear that he is in hortense's bedroom, probably looking for papers. oh, by the way, there is one thing i forgot to mention. it is a photograph i found in the french maid's room. it gave the clue to the greater part of my discovery. perhaps i had better show it you."
"i should like to see it very much," tanza murmured.
grey produced the torn photograph from his pocket and, with the aid of a match, exhibited it to his companion. he would have liked to know who was the other figure in the photograph. but that did not much matter, and it was a point which was not likely to be elucidated. then the two friends crept quietly into the house. it was not easy to grope their way upstairs in the dark, but they managed it without noise, and presently stood outside the room, watching rent at work. he seemed to be wrapped up in his task to the exclusion of everything else. he was pacing round and round the room, tapping on the panels and measuring distances with an iron lever in his hand. he was muttering to himself, too, but it was by no means easy to catch what he said. a quarter of an hour passed in the seemingly futile task, and then the searcher appeared to come to some definite conclusion. with a muttered exclamation he drove the point of his lever into one of the panels, and with a crackling, splintering sound the timber gave way. so far as the watchers could see, there was a space behind the panel more or less filled with letters. these rent stowed away in his pockets. beyond question, the object of his search was satisfied, for the expression of his face changed and a gleam of gratification sparkled in his eyes. he turned to the door so abruptly that tanza and his companion had barely time to fall back into the doorway of an empty room before rent began to descend the stairs. they watched him carrying the candle till he reached the basement of the house.
"what are you going to do now?" tanza asked.
"follow him," grey said curtly. "in point of fact, i promised to take him home. practically, though behaving like a sane man, the cloud is over his brain still, and i doubt very much if he knows what he is doing. of course, there is a good deal of method in his madness. still, we have to deal with a man who is not altogether accountable for his actions."
"and where do i come in?" tanza asked.
"oh, you'll go back to the yacht and wait further developments. it won't be very long before i am there again. and when i do come i may bring one if not two visitors with me. it might be necessary to do a little amateur kidnapping, but i am not sure about that yet. and now you had better leave me."
"all right," tanza said cheerfully. "i am content to leave matters to you. good luck to you!"
grey walked after the other figure. he laid his hand upon rent's arm and accosted him.