But the muddle was a deeper one within the next few minutes.  He crossed over to his hotel, and as he was entering he met Mrs. Marlow coming out, fresh, dainty, charming, as usual.  She stopped at sight of him and held up the little hand-bag which hung from her wrist.

“Oh, Mr. Allerdyke!” she said, opening the bag and taking an envelope from it.  “I’ve something for you.  See—­here’s the photograph your cousin gave me.  You were wrong, you see—­there’s no spot in it—­it’s a particularly clear print.  Look!”

In Allerdyke’s big palm she laid the very photograph which, according to all his reckoning, was that which Chettle had found within the cover of Lydenberg’s watch.

CHAPTER XXIII

THE POSSIBLE DEATH WARRANT

“Quite a clear print, you see,” repeated Mrs. Marlow brightly.  “No spot there.  You must have been thinking of another.”

“Aye, just so,” replied Allerdyke absentmindedly.  “Another, yes, of course.  Aye, to be sure—­you’re right.  No spot on that, certainly.”

He was talking aimlessly, confusedly, as he turned the print over in his hand, examining it back and front.  And having no excuse for keeping it, he handed it back with a keen look at its owner.  What the devil, he asked himself, was this mysterious woman playing at?

“I’m going to have this mounted and framed,” said Mrs. Marlow, as she put the photograph back in her bag and turned to go.  “I misplaced it some time ago and couldn’t lay hands on it, but I came across it by accident this morning, so now I’ll take care of it.”

She nodded, smiled, and went off into the sunlight outside, and Allerdyke, more puzzled than ever, walked forward into the hotel and towards the restaurant.  At its door he met Fullaway, coming out, and in his usual hurry.

Fullaway started at sight of Allerdyke, button-holed him, and led him into a corner.

“Oh, I say, Allerdyke!” he said, in his bustling fashion.  “Look here, a word with you.  You’ve no objection, have you?” he went on in subdued tones, “if Van Koon and I have a try for that reward?  It doesn’t matter to you, or to the Princess, or to Miss Lennard, who gets the reward so long as the criminals are brought to justice and the goods found—­eh?  And you know fifty thousand is—­what it is.”

“You’ve got an idea?” asked Allerdyke, regarding his questioner steadily.

“Frankly, yes—­an idea—­a notion,” answered Fullaway.  “Van Koon and I have been discussing the whole affair—­just now.  He’s a smart man, and has had experience in these things on the other side.  But, of course, we don’t want to give our idea away.  We want to work in entire independence of the police, for instance.  What we’re thinking of requires patience and deep investigation.  So we want to work on our own methods.  See?”

“It doesn’t matter to me who gets the reward—­as you say,” said Allerdyke slowly.  “I want justice.  I’m not so much concerned about the jewels as about who killed my cousin.  I believe that man Lydenberg did the actual killing—­but who was at Lydenberg’s back?  Find that out, and—­”