Influences of the Outsider is a written note found in Dishonored.
With an anxious heart, I respond to your letter. If your suspicion is true, I have grave misgivings about those presiding over Dunwall Tower. I have only recently resolved my disagreements with the Abbey, and it has come upon me as a surprise that some are lobbying for me to take up the mantle of High Overseer, but despite all that is going on, I hope to advise you personally in this matter.
Last time you wrote, you speculated that the mute who serves as torturer within Dunwall Tower might be a follower of the Outsider. He has an odd countenance, his tongue is twisted and he cannot speak, and a wolfhound follows him about. Add to this the incomprehensible groaning and the litany of repeated whispers you hear coming from his chamber at night, and it seems certain.
At first I found it hard to believe. How could one I admire so, such as the Lord Regent, allow this to go unchecked within his house? Surely he must respect the Seven Strictures? But now I see the pieces arranged before me. I must tell you, it aligns with a vision experienced by one of our sisters from the Oracular Sect. Coming to me in the night, she spoke, "Silence inflicts pain, and a hound's shadow follows the puppet of the Outsider."
Your position at the Tower has been of great use to our order, and there is no shame in reporting back to me. You are an Overseer, first and foremost, and it is your sole duty to protect the world of men from the malevolent influences of the Outsider. Tell no others of this, and await my instructions. I must wonder how high up into Dunwall Tower this corruption has spread.
It can be found in the Overseer shrine on the second floor of Dunwall Tower in the mission Return to the Tower.