The Sewers are the second area you reach in Dishonored, after escaping Coldridge Prison. This Dishonored Guide: How To Escape The Sewers Stealth Guide will show you how to get through the Sewers without any unnecessary kills or being seen.
Dishonored: How To Escape The Sewers Without Kills
Once you enter the Sewers you’ll hear a couple of guards talking. Don’t worry about these, the Rats make rather short and brutal work of them. You’ll see a note on some crates, read the note and then climb the boxes to the top of the cage. Sneak ahead and look below to watch the Rats at work, then continue forward. Eventually you’ll come across some Rats eating another corpse, attack these with your sword as soon as you can as they’ll head for you straight after. Then jump down into the water and swim through to the next room.
Once through the tunnel climb the side and cross the small plank to the two dead bodies, there’s a book nearby. Cross back over the plank and continue forward. Move the body blocking the crank and then open the gate. As you move forward you’ll see two bodies dropped from above, head over to that platform. You can throw a couple of the bodies down onto the floor to distract some of the Rats, but you’ll have to kill them all eventually anyway. Dispatch of the rodents and then open the gate. Just before you climb the chain look to your left for some good and small bit of coin. Check to your right at the top of the chain for some Copper Wire and a nearby Tripwire. Sprint and then enter Stealth Mode to dodge under the Tripwire for some coin. You can also disarm the trap itself for some ammo for your Crossbow. Stick to the right side to avoid the trap on the stairs and gather more coin. Then check the opposite side for your new equipment and some coin on the bodies.
Proceed through the gate with your key and slide under the trap using the same technique as before. You’ll see a note and a safe. The clue for the note doesn’t make a difference but look ahead at the bookcase and you’ll see the numbers 451 written behind some Whiskey bottles. Enter that code for the safe for some more coins. Continue forward until you hear some voices. Quickly search the room for a potion and bit of coin before dropping down. Drop down to the second rock and wait for the guard to face the railing, then drop down and take him out with a silent takedown. Ignore the prompt to do the aerial assassination. If you drop down literally as he says “Bastard”, you can subdue him and leave the body before subduing the other guard. Grab both bodies and place them at the bottom of the rocks. Continue forward and climb the rocks to the left, next to the planks.
You can be ballsy here if you want but there’s not much about so just follow the rocks around and climb onto the pipes. Check the pathing of the guards and as soon as they have their backs turned, drop down into the water and swim ahead to the broken grate. Continue forward and open the large Trash Bin near the two wrapped bodies, proceed. Exit the Sewers and speak with Samuel to leave.
Following this guide you should get the Ghost & Didn’t kill anyone bonuses, as well as the Special Action of opening Jelly’s Safe.