A strange disappearance

"Talking of sudden disappearances the one you mention of Hannah in that Leavenworth case of ours, is not the only remarkable one which has come under my direct notice. Indeed, I know of another that in some respects, at least, surpasses that in points of interest, and if you will promise not to inquire into the real names of the parties concerned, as the affair is a secret, I will relate you my experience regarding it."