"Yes," answered Chettle, taking up his glass and silently bowing his acknowledgments. "I have! The only one I could come to. The man who sent this photograph to Lydenberg, to help him to identify your cousin at sight, is the man who afterwards lured Lydenberg into that part of Hull High Street, and shot him dead. In plain words, the master shot his man--when he'd done with him. Just as he poisoned the Frenchwoman--when he'd done with her. Mr. Allerdyke, I'm more than ever convinced that these two murders--Lydenberg's and the French maid's--were the work of one hand." "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.