"That should be followed up, more," continued Brent. "There's no doubt whatever that that handkerchief, which Wellesley admits is his, got sent by mistake to one or other of Mrs. Marriner's other customers. That's flat! Now, you can trace it."
"How?" exclaimed Hawthwaite. "A small article like that!"
"It can be done, with patience," said Brent. "It's got to be done. That handkerchief got into somebody's hands. That somebody is probably the murderer. As to how it can be traced—well, I suggest this. As far as I'm conversant with laundry matters, families, such as Mrs. Marriner says she works for, have laundry books. These books are checked, I believe, when the washing's sent home. If there's an article missing, the person who does the checking notes it; if a wrong article's enclosed, that, too, is noted, and returned to the laundry."
"If Wellesley's handkerchief got to the wrong place, why wasn't it returned?" demanded Hawthwaite.
"To be sure; but that's just what you've got to find out," retorted Brent. "You ought to go to Mrs. Marriner's laundry and make an exhaustive search of her books, lists, and so on till you get some light—see?"
"Mrs. Marriner has, I should say, a hundred customers," remarked Hawthwaite.
"Don't matter if Mrs. Marriner's got five hundred customers," said Brent. "That's got to be seen into. If you aren't going to do it, I will. Whoever it was that was in that Mayor's Parlour tried to burn a blood-stained handkerchief there. That handkerchief was Wellesley's. Wellesley swears he was never near the Mayor's Parlour. I believe him! So that handkerchief got by error into the box or basket of some other customer of Mrs. Marriner. Trace it!"
He rose and moved towards the door, and Hawthwaite nodded.
"We'll make a try at it, Mr. Brent," he said. "But, as I say, to work on a slight clue like that——"