"If you carry on this inquiry, Doctor," he said, "it will be a very risky proceeding--I can tell you that much."

"What! Your object then is to frighten me into inactivity, Mr Mullet-- eh?" asked the little man, jumping up.

"Not at all--not at all, my dear fellow. You don't understand. You and I are friends, and--well, we'll continue to be, if you will allow me."

Raymond Diamond confessed that he did not understand the object of his visitor's presence there.

But "Red Mullet" only laughed, and taking another cigar from his case, said drily:

"Then let us drop the subject, Doctor, and talk of something else."

CHAPTER TWENTY.

THE INQUISITOR.

The police inquiries into the whereabouts of Gwen Griffin had been futile.

The Professor, beside himself with grief and apprehension, complained most bitterly that the authorities had not treated his daughter's disappearance with sufficient seriousness. In all the interviews he had had, both at the local police-station and at New Scotland Yard, the officials had apparently taken the view that the girl had left home of her own account. He had been told on all hands that, in the end, her escapade would be found to be due to some unknown love-affair.

In frantic bewilderment he had telegraphed to Frank Farquhar at the Bristol at Copenhagen, but unfortunately he had not received the message because on arrival at the Danish capital he had found the Bristol full, and had gone on to the Angleterre. Hence he was still in ignorance of the disappearance of his well-beloved.

Those mystic figures which the Professor had found scrawled upon his blotting-pad--the same that were upon that discarded sc.r.a.p of waste-paper--also puzzled him to the point of distraction. Could they have anything to do with the girl's fate? By whose hand had they been traced?

As far as they could discover, no stranger had entered the study. Yet those figures--"255.19.7"--had been written boldly in blue upon the pad.

Could Gwen have done it herself? Had she left him some cryptic message which he now failed to decipher? But if so, why did those same numbers appear upon the sc.r.a.p of paper discarded by the unknown man who was endeavouring to learn his secret?

After three days, during which time he puzzled over the meaning of those figures, applying to them all sorts of ciphers, he took a taxi-cab to a friend of his named Stevens, who lived at Streatham and was a Professor of Hebrew at London University.

The pair sat together for some time, Griffin having apparently called to pay a formal visit to his less ill.u.s.trious _confrere_, when suddenly producing the figures upon a piece of paper he sought Professor Stevens'

opinion as to their meaning.

The other stared at them through his spectacles, and after a long consideration inquired:

"Were they written by a Hebrew scholar?"

"I believe so."

"Then I think their meaning must be quite plain," replied the other coolly. "I should decipher it as the duration of the Kingdom of Israel.

Did it not end after 255 years--namely from B.C. 975-721--under nineteen kings and seven dynasties, not reckoning among the latter, of course, the ephemeral usurpations of Zimri and Shallum?"

"I never thought of that!" gasped Griffin. "Those figures have greatly disturbed me, my dear Stevens. They have appeared twice in circ.u.mstances extremely strange--traced by an unknown hand."

"But the hand of a scholar without a doubt," was the other's reply.

"Perhaps some crank or other who has the habit of signing himself in that manner. I have known men addicted to such peculiarities. There used to be a don at Oxford who had the humorous habit of appending his signature in most excellent imitation of that of Napoleon."

Griffin, recognising that Stevens was correct in his elucidation of the mysterious signification of those figures, became more puzzled. The man in search of the great secret was evidently a crank. That was most conclusively proved. Yet why should that mystic signature appear upon his blotting-pad?

Was it possible that Gwen and he were acquainted, and that he had actually entered the house.

The Professor was beside himself in his utter bewilderment. His daughter had slipped away, and left him without a word of farewell. Yet towards his friend Stevens he wore a mask, and only laughed heartily at the rapid solution of the problem which he had placed before him.

Was it possible, he thought many times, that Gwen, with a love-sick girl's sudden yearning, had slipped across to the Continent to join her lover? There could be no reason whatever for that, because he had never for a moment opposed their engagement. Yet girls were a trifle wild sometimes, he reflected, especially motherless girls like the dainty Gwen.

After an hour, however, he bade farewell to Stevens, and re-entering his "taxi" in King's Avenue, drove back into London, refusing his friend's invitation to remain for luncheon.

He crossed Westminster Bridge, and alighted at the British Museum to inquire if the mysterious searcher had been seen there of late.

The a.s.sistant-keeper in the Oriental room replied in the affirmative.

The old gentleman had been there three days before, and had afterwards gone to the great reading-room.

Proceeding there. Professor Griffin quickly made inquiries, discovering presently that the man had given the name of Rosenberg. He was shown a slip upon which was written the t.i.tles of the two rare works he had consulted. They were:

"Cryptomengsis Patefacta (1685)," and "Kryptographik, Kluber (1809)."

These were, he recognised, the two leading works on cryptography, explaining, as they did, all the early systems of secret writing from the _scytalc_ in use by the early Greeks down to the biliteral cipher of Sir Francis Bacon. It was therefore quite plain that the stranger, whoever he might be, though at Oxford he had made those calculations in order to test the existence of a numerical cipher in the Book of Ezekiel, had not yet discovered any true key.

This knowledge gave Griffin great satisfaction. The loss of that crumpled paper from his pocket was, he recognised of no import.

Inquires of the librarian showed that the stranger was not known in the reading-room as a regular reader. Yet he agreed, as indeed had other librarians and keepers of ma.n.u.scripts, that the old man was undoubtedly a scholar.

This person's will-o'-the-wisp existence was most tantalising. In appearance he was described as an old white-headed man with deep-set eyes and a longish white beard, rather shabbily dressed and wearing a long black overcoat much the worse for wear. Great scholars are not remarkable for their neatness in dress. They are mostly neglectful, as indeed was Professor Griffin himself. To Gwen, her father was a constant source of anxiety, for only at her supreme command would he even order a new suit, and his evening clothes were so old and out of shape that she had, times without number, declared herself ashamed to go out to the smart houses at which they were so often asked to dine.

But genius is always forgiven its garments, and the fact that the bearded stranger was described as shabby and almost threadbare did not surprise the man who went about equally shabby himself.

If he were interested in the "Cryptomengsis Patefacta," then one thing was proved. His researches at the Bodleian had been without result.

The continued absence of Gwen, however, prevented Griffin from continuing his inquiries. Though times without number he opened the Hebrew text of Ezekiel and tried to study it, yet he was unable to concentrate his mind upon it, and always closed the book again with a deep sigh.

The house was dull and empty without little Gwen's bright smile and musical voice. This, he realised, was a foretaste of his loneliness when she was married.

Next day dragged by. The following day was cold and wet, and he spent it mostly alone in his study, after he had been round to the police-station and obtained a negative reply to his question as to whether his beloved daughter had been discovered.

That she was absent against her win he was convinced. She would never have left him in that manner to allow him to fear for her safety.

Seated alone, he brought out those large photographs of Diamond's half-destroyed ma.n.u.script, and tried to centre his mind upon them. But, alas! he was unable. Therefore, as the short grey afternoon drew in, with a sigh he rose, put on his overcoat, and telling Laura he would not be back to dinner, he went forth to wander the London streets. He could bear the dead silence of that house no longer.

Just before seven o'clock the dining-room bell rang, and the dark-eyed parlour-maid, ascending the stairs, entered the room.

"Lor', miss!" gasped the c.o.c.kney girl. "You did give me a fright! How long have you been 'ome?"

Gwen, who stood before her, pale and thin-faced and with hair slightly dishevelled, explained that she had just let herself in with the latch-key.

"The Professor's out, miss. 'E said 'e wouldn't be 'ome to dinner," the girl remarked. "Oh, we've been very worried about you, miss! The perlice 'ave searched 'igh and low for yer. We all thought something dreadful 'ad 'appened. Wherever 'ave you been all these days?"

"That's my own business," answered the Professor's daughter. "I've come back safe and sound, and I'm now going to my room. Tell my father when he comes in that I'm very tired. Perhaps he won't return till late."

"Shall I bring you up something, miss?" asked the girl.