“Likely!” assented Allerdyke.  “It’s getting to look like it.  But—­whose?  That’s the problem, Chettle.  Well, I’ve done a bit since I got back this afternoon.  You’ve had something to tell me—­now I’ve something to tell you.  I’ve found out who it was that James gave the photograph to!”

Chettle showed his gratification by a start of pleased surprise.

“You have—­already!” he exclaimed.

“Already!” replied Allerdyke.  “Found it out within an hour of getting back in here.  He gave it”—­here, though the door was closed and bolted, and there was no fear of eavesdroppers, he sank his voice to a whisper—­“he gave it to Fullaway’s secretary, the woman we discussed, Mrs. Marlow.  That’s a fact.  He gave it to her just before he set off for Russia.”

Chettle screwed his lips up to whistle—­instead of whistling he suddenly relaxed them to a comprehending smile.

“Aye, just so!” he said.  “I was sure it lay somewhere—­here.  Fullaway himself, now—­does he know?”

“James gave it to her in Fullaway’s presence,” replied Allerdyke.  “She’s a bit of a photographer, I understand—­they were talking about photography, I gathered, one day when James was in Fullaway’s office, and James pulled that out and gave it to her as a specimen of my work.”

“All that came out in talk this afternoon?” asked Chettle.

“Just so.  Ordinary, casual talk,” assented Allerdyke.

“No suspicion roused?” suggested Chettle.

“I don’t think so.  Of course, you never can tell.  I should say,” continued Allerdyke, “that she’s as deep and clever as ever they make ’em!  But it was all so casual, and so natural, that I don’t think she’d the slightest idea that I was trying to get at anything.  However, I found this much out—­she couldn’t produce the photograph.  Said she’d taken it home.  Well—­there we are!  That’s part one of my bit of news, Chettle.  Now for part two.  This woman’s leading a double life.  She’s Mrs. Marlow as Fullaway’s secretary and here at his rooms and on his business; where she lives she’s Miss Slade.  Eh?”

Chettle pricked his ears.

“When did you find that out?” he asked.  “Since you left me this morning?”

“Found it out this afternoon,” replied Allerdyke, with something of triumph.  He had been strolling about the bedroom up to that moment, but now he drew a chair to the table at which Chettle sat and dropped into it close beside his visitor.

“I’ll tell you all about it,” he went on.  “You said at Hull yesterday that you’d always found Yorkshiremen sharp and shrewd—­well, this is a bit more Yorkshire work—­work of my manager here in town—­Mr. Appleyard.  Listen!”

He gave the detective a clear and succinct account of all that Appleyard and his satellites had done, and Chettle listened with deep attention, nodding his head at the various points.

“Yes,” he said, when Allerdyke had made an end, “yes, that’s all right, so far.  Good, useful work.  The thing is—­can you fully trust these two young men—­your chauffeur and his brother?”