Okay - again 'spoiler alert':
RDR calls it 'Faded Letter' - it was in a tin box on the spoonbill island (the one nearest Sisika Penitentiary on a line directly east from the word LAGRAS in the bayous.
Letter to Douglas Gray from Lucille Braithwaite
June 12th 1806
My Dearest Douglas,
The mere act of writing your name weakens me with longing. My exile in Connecticut has endured barely three weeks but it already feels like a lifetime since I saw your wonderful smile. Why should the family into which I was born, and a surname that was imposed on me, dictate whom I can and cannot love? Like you always say, however, there are so many less fortunate than ourselves and subject to far worse partiality and narrow-mindedness.
Please take all that gold to the group I told you about. It should provide them with enough funding for another two years of operation so they can keep pressure on Congress to abolish the importation of slaves into this country once and for all. Our two families are so blinded by avarice and bitterness that either they will not realize it is missing or they will assume the other has stolen from them.
Then come for me, my love, as we planned, and we will flee somewhere far away, down to South America or across Europe, where we can simply live as Douglas and Lucille, not as Master Gray and Miss Braithwaite.
Yours always,
Lucille