He had paused, absorbed in meditation. The young girl also was silent. Some memory too vague as yet to take a definite form was persistently haunting her — one thought was hammering away in her brain, and playing havoc with her nerves. That thought was the inexplicable feeling within her that there was something in connection with that hideous crime which she ought to recollect, something which — if she could only remember what it was — would give her the clue to the tragic mystery, and for once ensure her triumph over this self-conceited and sarcastic scarecrow in the corner.

He was watching her through his great bone-rimmed spectacles, and she could see the knuckles of his bony hands, just above the top of the table, fidgeting, fidgeting, fidgeting, till she wondered if there existed another set of fingers in the world which could undo the knots his lean ones made in that tiresome piece of string.

Then suddenly — á propos of nothing, Polly remembered — the whole thing stood before her, short and clear like a vivid flash of lightning: — Mrs. Owen lying dead in the snow beside her open window; one of them with a broken sash-line, tied up most scientifically with a piece of string. She remembered the talk there had been at the time about this improvised sash-line.

That was after young Greenhill had been discharged, and the question of suicide had been voted an impossibility.

Polly remembered that in the illustrated papers photographs appeared of this wonderfully knotted piece of string, so contrived that the weight of the frame could but tighten the knots, and thus keep the window open. She remembered that people deduced many things from that improvised sash-line, chief among these deductions being that the murderer was a sailor — so wonderful, so complicated, so numerous were the knots which secured that window-frame.

But Polly knew better. In her mind's eye she saw those fingers, rendered doubly nervous by the fearful cerebral excitement, grasping at first mechanically, even thoughtlessly, a bit of twine with which to secure the window; then the ruling habit strongest through all, the girl could see it; the lean and ingenious fingers fidgeting, fidgeting with that piece of string, tying knot after knot, more wonderful, more complicated, than any she had yet witnessed.

"If I were you," she said, without daring to look into that corner where he sat, "I would break myself of the habit of perpetually making knots in a piece of string."

He did not reply, and at last Polly ventured to look up — the corner was empty, and through the glass door beyond the desk, where he had just deposited his few coppers, she saw the tails of his tweed coat, his extraordinary hat, his meagre, shrivelled-up personality, fast disappearing down the street.

Miss Polly Burton (of the Evening Observer) was married the other day to Mr. Richard Frobisher (of the London Mail). She has never set eyes on the man in the corner from that day to this.