wards of the lock were lifted.

  In another moment the pair stood within the brightly-lit hall, and thedoor was closed noiselessly behind them.

  Standing there, within a few yards of the door of the library, wherefrom the smell of tobacco smoke it was evident that old Sam was takinghis ease, they were in imminent risk of discovery. Besides, Levi had ahabit of moving without sound in his old felt slippers, and might at anymoment appear up the stairs from the lower regions.

  Instinctively Charlie glanced upstairs towards the locked door. Butnext second he motioned his companion to follow, and stole on tiptoeover the thick Turkey carpets past the millionaire's door and on into akind of small conservatory which lay behind the hall and was indarkness.

  Though leading from the room behind the library, it was a fairly goodspot as a place of hiding, yet so vigilant was old Levi that the chanceswere he would come in there poking about ere he retired to rest.

  The two men stood together behind a bank of what had once beengreenhouse plants, but all of them had died by neglect and want of waterlong ago. The range of pots and dried stalks still remained, forming aneffectual barrier behind which they could conceal themselves.

  Through the long French window of the room adjoining the light shone,and Charlie, slowly creeping forward, peered within.

  Then he whispered to his friend, and both men bent to see what wastranspiring.

  The scene was unusual.

  A full view of the library could be obtained from where they stood inthe darkness. In the room two of the big armchairs had been pulled up,with a small coffee table between them. On one side was old Sam, lazilysmoking one of his big cigars, while on the other was Levi, lying back,his legs stretched out, smoking with perfect equanimity and equally withhis master. Upon the table was a decanter of whisky and two glasses,and, judging from the amused countenances of both men, Sam had beenrelating to Levi something which struck the other as humorous.

  It was curious, to say the least, that Levi, the humble, even cringing,servant should place himself upon an equality with his master. That hewas devoted to old Sam, Charlie knew well, but this friendship he hadnever suspected. There was a hidden reason for it all, without a doubt.

  The two intruders watched with bated breath, neither daring to make asound.

  They saw Levi, his cigar stuck in the side of his mouth, lean back andthrust his hands deep into his trousers-pockets, uttering some wordswhich they could not catch. His manner had changed, and so had Sam's.From gay the pair had suddenly grown grave. Upon the millionaire's browwas a dark shadow, such as Charlie, who knew him intimately in all hismoods, had seldom seen there.

  Levi was speaking quickly, his attitude changed, as though givingserious advice, to which his master listened with knit brows and deepattention. Then, with a suddenness that caused the two watchers tostart, the electric bell at the hall-door sounded.

  In an instant Levi tossed his cigar into the fire, whipped off his glassfrom the table, and in a single instant became the grave family servantagain, as with a quick gesture of his hand he left the room to answerthe summons at the door.

  In a few moments he returned, closing the door quickly after him, sothat whoever was in the hall could not overhear what was said.

  Approaching his master he made some announcement in a whisper, whereatthe millionaire clenched his fist, and struck violently in the air.Levi urged calmness; that was evident from his manner.

  Then Sam, with a resigned air, shrugged his shoulders, paced the room inquick agitation, and turned upon his servant with his eyes flashing withanger.

  Again Levi placed his thin hand on the old man's arm which calmed himinto almost instant submission.

  Then the grave-faced old servant went out, and an instant later usheredin a woman, all in black--a woman who, in instant, both Max and Charlierecognised.

  They both stood watching, breathless--rooted to the spot.

  The mystery, as they afterwards discovered, was even greater than theyhad ever anticipated.

  It was beyond human credence.

  CHAPTER FORTY SEVEN.

  CONTAINS MORE MYSTERY.

  The old-fashioned, ill-cut gown of black stuff and the rather unbecomingbig black hat gave Sam's visitor an appearance of being older than shereally was. A spotted veil concealed her features, but as she enteredthe room she raised it quickly.

  The face revealed was the soft, sweet countenance of Maud Petrovitch.

  Charlie gripped his companion's arm and gave vent to an exclamation ofamazement as he stood peering forth open-mouthed.

  As the girl entered the old man turned fiercely upon her and utteredsome inquiry. What it was the watchers could not distinguish, for thickplate glass stood between the conservatory and the library. Yetwhatever he said or however caustic and bitter his manner, the younggirl stood defiant.

  Her chin was raised, her eyes flashed upon him, and her gloved hand wasoutstretched in a gesture of calm denunciation as she replied with somewords that caused the old fellow to draw back in surprise and confusion.

  The door had closed, for Levi had left the pair together. Max wonderedwhether the old servant would now come and search the back premisesprior to locking up. If so, they might easily be discovered. Thosefelt-soled boots of old Levi struck fear into their hearts. Charliewas, however, too occupied in watching the old man and the girl at thatmoment to think of any danger of detection.

  His well-beloved stood pale, beautiful, and yet defiant before the manwho a moment before had shaken his fist and clenched his teeth onhearing of her demand to see him. The words she had uttered had causedan instant change in his manner. His sudden anger had been succeeded byfear. Whatever she had said was evidently straight to the point.

  For a moment he regarded her in silence, then over his grey face came acrafty smile as with mock courtesy he offered her a chair, stillremaining standing himself.

  She leaned her elbow on the arm of the chair, and, bending towards him,was speaking again, uttering slow, decisive words, each of which seemedto bite into his very soul. His countenance again changed; from mockhumour it became hard, drawn, almost haggard.

  Charlie, who knew the old man in every mood, had never witnessed such anexpression upon his face. Beneath it all, however, he detected a lookof unrelenting, almost fiendish revenge. He longed to rush forward andgrasp his loved one in his arms, but Max, seeing his agitation, laid hishand firmly upon his shoulder.

  "Let us watch in patience, Charlie," he urged. "We may learn somethinginteresting."

  Maud had altered but little since that afternoon when, in the haze ofthe red London sunset, Charlie had last walked with her in NevernSquare. She was, perhaps, a trifle pinched in the cheeks, but the sweetdimples were still there, and the little wisp of hair still strayedacross her white brow. Her gown, however, seemed shabby andill-fitting. Perhaps she had borrowed it in order to come there ingarments by which she would not be recognised. For a young girl to makea visit at that late hour was, to say the least, somewhat unusual.

  Both men standing in the shadow behind the thick glass longed to hearwhat the pair were saying. It was tantalising to be so near thedisclosure of a secret--indeed, to have it enacted before one's eyes--and yet be debarred from learning the truth.

  Max examined the door, hoping to open it ever so slightly, but to hischagrin he found it locked and bolted. Old Levi had already prepared toretire before they had made their surreptitious entrance there.

  That he had at last found Maud again was to both a source of immensegratification. At last the truth of the doctor's strange disappearancewould now be known. But what connection could old Statham have with theaffair?

  Charlie recollected what Sir Charles Harrison had told him in Belgrade--that the bomb outrage by which a poor innocent child had lost her lifehad been planned by one of his friends.

  He had suspected Max. But in the light of Maud's secret visit toStatham, he now held the last-named in distinct suspicion. Was it partof the m
illionaire's cunning policy in Servia to rid the country of itsgreatest statesman?

  No. That was impossible. The Doctor and Statham had been friends.When Petrovitch was in power they had worked hand-in-glove, with theresult that the millionaire had lent money to the Servian Governmentupon very second-class security. Unrest in Servia would, Charlie waswell aware, mean loss to Statham Brothers of perhaps a million sterling.It was therefore to the interest of the firm that the presentGovernment should remain in power, and that the country should beallowed to develop and progress peacefully.

  He tried to put behind him that increasing suspicion that Old Sam wasthe "friend" to whom the diplomat had so mysteriously referred.

  And yet as he watched every movement, every gesture of the pair withinthat long room where the lights were so artistically shaded--the roomwherein deals involving the loss or gain of hundreds of thousands ofpounds were decided--he saw that the girl remained still defiant, andthat the man stood vanquished by her slow, deliberate accusation.

  Old Sam's bony fingers were