To Daud is a written note found in Dishonored: Death of the Outsider.
Transcript[]
I'm writing this while you sleep. You still snore. Talk sometimes, too. Mutter. I didn't know what you'd be like when I found you again, but you're just as troubled as you were when I left Dunwall.
Could things have been different? I always wondered what I could have been if I hadn't tried to kill you that night. If I'd stayed and helped you. Would the Whalers still be a part of Dunwall's nightmares? Would you still want the Outsider's blood on your hands?
Maybe you had a few good years before you let this new obsession eat you up. Now you'll risk everything for it, won't you? By the Void, I'm laughing. When I was a kid, I wanted to be just like you. Well, now I am.
Maybe killing the Outsider will let you find some peace at last. Maybe that's all you want, to know that everything we did at least made some kind of difference. That it wasn't all just death. That all the faces we stepped on paved the way to a fairer world.
Maybe that's the only hope you have left.
Location[]
It can be found in the water near the Dreadful Wale in the beginning of Follow the Ink mission.