Masterfully guessed, as always! Thank you for your kind comments; I do not mind in the least being known for giving Mary her due. I remember writing the journal entries about Dynamics and wondering if you'd nail me for that particular headcanon, but I honestly thought it was the backstory set in Nelson's navy that was going to be the anonymity-buster. (After you made this guess, I said to my beta that maybe I should get myself some new mathematical headcanons for Moriarty? She replied that it wouldn't help; I'd still write Moriarty like someone who had informed opinions about mathematics.)