Traitors Keep – Heroes and Villians
Head from Mary's cell to the nearby Records Room. You will find a beat-up Milton. He will tell you that Turner never actually left the island. That he had, instead, been getting around it using various hidden passages in the Keep. The good news, in a sense, is he took Hobson. Still, you need to find him and see what he wants. Milton will point you to the door that he used to make his escape with Hobson, in the back of the Records Room.
At the bottom of the stairs leading to Turner, out of the Records Rom, you will find a chest. Open it to find a Health Potion sitting inside. Not too far from it, you will also find one of Turner's diaries. There are few more to find around the area, so keep an eye out for them (or just pay attention here).
After that, follow Milton through the adjacent boiler room and through to the other side of it. There is nothing of note in this room, or up the stairs on the far side. Simply go forward through the door on the other side, near the boiler and the coffins. This leads to a level corridor and a cut scene. Turner will loose the asylum prisoners on you, who will come charging with weapons drawn and guns blazing.
At the conclusion of the fight, your long-time ally for this fight, Milton will be wounded enough he cannot continue. He will bid you to go on, confront Turner and free Hobson. He tells you he will hold them off as well as he can. Time for you to sprint down the corridor and through the doors. When you reach the Torture Chamber you will find Hobson strapped to the chair, gagged, and rigged up. Walk up to him and untie him. Milton makes another appearance, this time showing his true colors. That there was no other prisoner, it was Milton all alone. He unleashes the electrical fury of the chair on you, blasting you off the platform and into unconsciousness.
After this, you will come to strapped into the other chair, Milton begins to reveal the plan that he was a part of. Turner apparently died six months ago and Milton considered him the best officer that he had ever served under. He puts forth the query of how do you bring down a Hero, the answer is apparently by becoming one. He will zap you, and it is revealed that the machine that Mary used on the Hobbes and company is the same model you are now strapped into. Some of your essence is siphoned off and put into a potion that Milton will now drink. He will become the opposite of your character, complete with all your powers. This does not look good for a fight. The man will conjure a fireball, tell you that only one of you can live, and then blast your dog! Time for some smack down.
This battle will prove to be challenging, even to Fable veterans. It is very rare that you actually fight another hero, much less one that is you. As the battle wears on, he will reveal his plot to take over the throne as you, to reverse all your bad decisions and dissolve the monarchy to free Albion of it and set it to the will of the people with the military ready to guard it. You will want to use every trick that you have in this fight. Use the Slow Time and Summon creature potions, break somewhat from you typical style of combat and bring on as much pain as you can to Milton. It will take some time, but Milton will go down. He will tell that one day the people will claim their freedom from the crown. With that, you will earn the achievement, “Who Are You?” and are just about complete the DLC! There are still a number of things to be found around the island, so feel free to explore the area more thoroughly now.