She left off fussing the blankets and scooting about, like a cat circling on a bed before choosing where to curl up.

“You equate the problem at the bank with the irregularities in my books?” Rex surely hadn’t. One was neglect, the other bad luck, and ne’er the twain should meet.

“The coincidence is troubling.”

God save me. If Eleanora Hatfield was troubled over a coincidence, it wasn’t a coincidence. “I’ll tell you what’s troubling. Lord Jeremy Bledsoe seeking to pay my sister his addresses is troubling.”

“He’s not suitable?”

“He is suitable. My sensible, prudent sister has likely fallen for his lordship, and once they’ve shared a few waltzes—a few more waltzes—the solicitors will begin the negotiations. The dower properties will be examined under multiple quizzing glasses, and the only estate I can honestly vouch for is Ambledown.”

Which Rex had promised to the lady sharing a coach with him. She’d brushed his offer aside, though for salvaging a dukedom, Eleanora Hatfield deserved more than a few pounds and ink-stained fingers.

“Impending negotiations do present a challenge.”

“What a gift for understatement you have developed. The honorable Mr. Hornby is making calf eyes at my sister Lady Samantha, and even Lady Kathleen is apparently inspiring bad sonnets.”

“All three at once, Your Grace?”

“So it would appear. Tell me about compound rounding.”

She rustled about some more. “The concept is straightforward. If you invest a hundred pounds at five percent, then calculating the interest is simple.”

“Five pounds,” Rex said, as the coach picked up speed.

“But what if the sum invested is an odd number? Say, eleven pounds and five pence?”

“You deal in farthings.”

“Or, if I end up with an odd number of farthings, I must eventually deal in decimals and rounding. If I consistently round down, while keeping a tally of all the pennies that result, the cash drawer will eventually have a greater sum than the ledger sheet reflects.”

“But one doesn’t round downward unless the figure is below five. Otherwise, one rounds upward, and the two exercises eventually cancel each other out.”

Perhaps Mrs. Hatfield was less self-conscious when discussing embezzlement, perhaps she yielded to the animal temptation to draw nearer to warmth, but draw nearer to Rex, she did.

“To detect a scheme of this nature,” she went on, “you’d have to double-check every calculation and every rounding. To be productive, a compound rounding rig should be spread over many active accounts, at least hundreds.”

What sort of mind devised these schemes? “The bank has thousands of accounts.”

Mrs. Hatfield yawned behind her hand. “I beg your pardon. I was up late last night.”

“Working on ledgers? I thought you took the Sabbath off.”

“I could not resist the lure of your family seat, Your Grace. You will be relieved to know the books are holding up to scrutiny.”