He was always able to talk of them for any length of time. He could not get over the mystery, could not forgive himself the blunder, could not rest without solving the riddle of the lost half-sheet. Postscripts haunted him night and day. He was like an ardent devotee of conundrums—unable to enjoy life till he should find a clue to the puzzle.

Nigel had to listen to a new and profuse statement of all the details, wound up by a graphic description of his questions put to Fulvia, and of her emphatic denial.

"Said plainly enough she hadn't received yours—hadn't received any postscript at all, in fact. What do you think?"

"It settles the matter, of course, once for all." Nigel spoke with a touch of impatience, for he was tired of the subject.

"Unsettles the matter, you mean. Why, now, I have told you a dozen times at least—"

"Quite true," thought Nigel, with an inward groan.

"That there were four envelopes and four postscripts, and that I put one postscript into each envelope. Now, under those circumstances, how could Fulvia have failed to get one?"

"She evidently did fail."

"But I say, my dear fellow, she could not!"

"You meant to put in the four. Whether you did so is another question. I suppose we all make mistakes sometimes. And Fulvia's word—"