The House of Pleasure is not as long as the High overseer mission unless you try to complete it without being seen or killing anyone.
The First thing you want to do is to spend some of your hard-earned cash from the previous two missions. If you’re focusing on making a long-range sniper Corvo, purchase the mask zoom, and upgrade the range on your preferred ranged weapon. Of course, how you build your character is entirely up to you and subjected to your play style.
Once equipped, go find Slackjaw at the brewery (keep an eye out for the Watchtower!); this is necessary if you want to complete the mission non-lethally. You can find a Slackjaw’s thug near the Bitterleaf’s Almshouse. He will take you to the entrance of the distillery. Slackjaw can be found in the distillery’s reserve.
Slackjaw will also have two tasks for you. First, to find a missing gangster by the name of Crowley, and secondly to raid the contents of a safe owned by a certain artist. After meeting with Slackjaw, you must go to Dr. Galvani’s office.
Once you leave, you will find three Daud assassins waiting for you in the alley to the right of the distillery entrance. Use Dark Vision to reveal their positions. Two are in the rooms opposite to each other overlooking the road below while the third is stationed on the rooftop.
Knowing where these assassins are will really help you get past them undetected. Using Dark Vision and Blink to navigate through this alley is advisable. Use your crossbow to fire sleeping darts at the foes to take them out from a safe distance. This will also greatly decrease your chances of being spotted by them.
When you have taken down two of the three, one in the room to your left and the other on the rooftop, it would be safe for you to cross that alley. Go over to the downed assassin on the rooftop and look at the pipe beside him. Hop on it and go around the Art Dealers building to come in front of the door of the Doctor’s office.
Dr. Galvani’s office front door is protected by a lot of city watch guards. Going through that door can be difficult but not impossible. To the extreme left of the front door, there are stairs leading you down. From the Art Dealers’ balcony, use blink to hide behind covers and get to those stairs.
Go across the narrow alley pass under the staircase that leads to the front door. Now to your right will be two crates, jump on them and blink to the front door when the guard has his back turned to it. I cannot stress enough the use of Dark Vision to know the positions of the enemy guards.
Inside the office, you will find Crowley’s body on the third floor. Remember to pick Crowley’s last message from his corpse. There are a few guards in the office, but you can evade them easily.
Return to Slackjaw with Crowley’s audio graph and he will give you the key to Captain’s Chair Hotel. Through the roof of this hotel, you can gain access to the Golden Cat brothel. He will also offer you another way to deal with the twins but in this guide, we will assume that you turned down the offer.
Now you need to get into the brothel in order to make your way to the Captain’s Chair Hotel. From Clavering Boulevard, where Dr. Galvani’s was, turn right. Your path will be immediately blocked by Wall Of Light. There will be two city watch men guarding it.
Wait for one of them to leave and deal with the second one discreetly. Take out the oil tank from the generator to deactivate the wall. Diagonally left to the generator is light post, just beyond the wall of light.
Blink onto it and then speedily blink to the brown crates in front of you to avoid the search spotlight. Get down from the brown crates and take cover behind them. After that, immediately blink to take cover behind the city watch’s blue little booth. Across from the booth is the door to Captain’s Chair.
Once inside the Captain’s chair head to the stairs. The door to the Golden Cat will be at the very end of them. Beware there are a lot of rats on the stairs, who will attack you. To make it to the door, you need to have at least one health serum with you.
From the rooftops, you can easily gain access to the Golden Cat. Blink to one of the windows of the brothel then open the shutter and slip right in.
First order of business when you get into the brothel is to pickpocket the master key of the whole brothel from the madam in her office. Campbell’s journal says for you to visit the madam and get Emily’s location. After that find Emily. She will be in one of the small dormitories on the third floor.
Set her free and she will take you to a secret passage out of the brothel being blocked by a lock door but since you now have the master key that door should not be a problem for you.
Your targets are the Pendletons, and both are in separate rooms. The first is in the Ivory Room. Watch for the guards (choke out the peeping Tom and use the nearby balconies to stockpile bodies) and look for the balcony beside the Ivory room. From that balcony, you can jump to a ledge which leads you straight to the balcony of the Ivory room.
This will present you with a perfect opportunity to kill one of the twins from behind without alerting anyone else.
The second is in the Smoke room, and this kill can be a bit more devious. Just like the Ivory room, you can also access this room by an alternate route. From the balcony next to this room, jump on to the ledge, and it will take you straight to the balcony of the Smoke Room.
This will allow you to kill the second twin from behind instead of bursting through the door like a maniac. You can also instead visit the maintenance room next to the steam room. Put the valve wheel into the slot and turn it to boil the target alive.
After you have killed both twins, you need to go to the VIP entrance Emily showed you. That door will open up to the Distillery district and from there, just have to go back to Samuel. He is still at the spot where he dropped you off at the beginning of this mission, and Emily is with him.
Note. The alternate way to solve the twins’ problem is to sell them to Slackjaw, but for that you will have to honor his side missions.