Lady Boyle Missing is a written note found in Dishonored.
Our search for the missing Lady Boyle continues with limited results. No one seems to know what happened to her, though there was a rumor circulating that she left the party by boat. It seems unlikely, but in any case the witness in question saw nothing more, so even that lead went cold.
Also, it's undoubtedly not worth your time and I hesitate to even mention it, but apparently on the night of the Boyle Party someone signed the guestbook as "Corvo Attano". It must be a perverse joke, surely. However, you asked to be notified of all such matters, and in truth we never located the Royal Protector's body, so I thought best to bring it to your attention. Sorry for troubling you with this matter.
I know Lady Boyle is dear to you. Rest assured we will redouble our efforts to locate her.
If Corvo both chooses the non-lethal elimination and signs the guestbook in Lady Boyle's Last Party, this note will appear on the desk in the Lord Regent's quarters in Return to the Tower. If he does not sign the guestbook, the paragraph referring to this action will not appear.
An alternate note will appear if Corvo chooses the lethal elimination and signs the guestbook.