Anna Katharine Green 
A Strange Disappearance [EPUB ebook] 

‘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.’ The speaker was Q, the rising young detective, universally acknowledged by us of the force as the most astute man for mysterious and unprecedented cases, then in the bureau, always and of course excepting Mr. Gryce; and such a statement from him could not but arouse our deepest curiosity.