Be Warned is a written note found in Dishonored.
I found one of our brothers attempting to put a package in the post boxes for the others to find. I believe it to be the evidence of your sister’s involvement in witchcraft you spoke to me about. I attempted to stop him, but he insisted that I would burn for her crimes if I was attempting to cover her deeds. You should warn her. See if the two of you can flee the city before they reach her.
Your friend and brother.