At the end of Return to the Tower mission, you are betrayed by the Loyalist. They poisoned you and if it wasn’t for Samuel, you would have most likely been dead. However, Sam saves you and leaves you adrift in the Flooded District, helpless but still alive. A group of assassins find you and take you to their leader, “Daud.”
After a brief conversation with Daud in which he confesses assassinating the Queen and tells that he knows about the “Outsider,” you are knocked unconscious again.
You will wake up in the void, and this is where you will assume control over Corvo for the first time on this mission. Walk forward a bit and you will be greeted by the “Outsider” himself. After a brief cut scene with him, you will wake in a cell. In your cell, possess one of the two rats, drop down the rat tunnel and escape imprisonment.
Go up the stairs you see to your right once you come out of the rat tunnel. Do not forget to pick up an assassin’ blade which is on a table, with the wanted posters over it.
Use your blink ability to cover the distance where the stairs have a gap between them. There will be two guards on the top of the stairs. Use the Dark Vision and the Blink powers to your advantage to dispatch of the guards easily.
Now that you are on the top of your prison building, dive down into the waters of the Flooded District. Your first order of business is to retrieve your gear.
You need to get to Greave’s Refinery. Use your ability of Blink to stay on top of the water as you move from plank to plank.
There are killer fish in the water who will attack you and possibly kill you. There are three weepers by the door to the refinery. Take them out one by one. Use Dark Vision to locate them. There is also a fourth weeper in the alley to the left.
Go through the door to the next area and you will encounter a lot more weepers. However, you can evade them easily by using blink and staying on the rooftops as you make your way to your gear.
Follow your marker that says, “Your gear” and it will guide you through a path where no one can detect. Each time you get to the point where the marker leads you; it will act as a checkpoint.
You only have to look where the marker is leading you to find the right path ahead and in all cases, it is directly in front of you.
You will have to blink from a position to position, travel on pipes and climb chains, but ultimately, it will lead you to the inside of the refinery. Just before you can go inside you will overhear assassins talking about a way into Daud’s base through the rail station.
Once inside the refinery you need to lower the drawbridge. The drawbridge requires a fuel cell to activate it. There will be a machine that fills empty cells to your right. You can get an empty fuel cell in a small room straight ahead from the filling machine. However, it is blocked.
Use your melee attacks to destroy the planks and proceed into the room using blink to get an empty fuel cell. Toss the fuel cell over the bars and blink yourself out of the room. The fuel cell will not explode as currently it is empty. Carry the fuel cell to the filling machine and it will pour whale oil into it.