One of the tasks belonging to Phineas's questline is The City and the Stars. During it, you will have to infiltrate Byzantium's government structures. This page of the guide The Outer Worlds includes a walkthrough of this quest.
List of objectives
- Meet Phineas's contact;
- Talk to Minister Clark;
- Talk to the Minister's guards (optional);
- Receive the Minister's parcel from HPS (optional);
- Investigate the Chairman's office;
- Get Dimethyl Sulfoxide;
- Go back to Phineas.
The quest is activated immediately after completing the Radio Free Monarch quest. Phineas will ask you to obtain a substance called Dimethyl Sulfoxide. Its entire stock is in Byzantium and controlled by The Board. Finally, you will also get a navkey for the city docks.
Talk to Minister Clark
While heading to Byzantium, choose the landing pad at the docks. This way you can immediately talk to Phineas's contact - Carmen Imagawa. She will explain to you that Minister Clarke has Dimethyl Sulfoxide.
Your next goal is to get to the Minister's house. There are two ways to get there. The first is to go to the local bar. You will meet a guard named Mayfield. Talk to the guard and buy him 3 Spectrum Vodka. After that, he will go to sleep. You can take his key to the Minister's residence. You will have to use the residence's back doors. Otherwise, you will be stopped by a security guard.
The second option is to get inside while being disguised as a courier. If you talk to the security guard at the main entrance, you will learn that Clarke regularly receives parcels from HPS.
To get inside, you can go to the specified location. There, you can break into the warehouse and steal a package. Be careful not to be caught by the guard. Go to the residence with the package - you will be allowed inside.
During the conversation, you will learn that Dimethyl Sulfoxide is in possession of Chairman Rockwell. The Minister will also ask you to send a message to the Earth. If you agree, you will start The Lying Earth quest.
Investigate the Chairman's office;
Your next destination is the HHC building in the Acropolis. If you have completed Balance Due quest, you will get there without any problems. Otherwise, you will have to go through the tunnels - this solution requires Lockpick ability on a sufficient level.
When you get to the upper floor, head to the door located to the left of the office entrance. Open them with the key received from the Minister. Platt will talk to you but this doesn't mean you are in trouble.
Go through the hole in the wall - you will access Rockwell's office. Go to the terminal and read the message. Then, print the minister key. Now you can go to the Ministry of Accuracy and Morale.
Get Dimethyl Sulfoxide
Dimethyl Sulfoxide is stored in the Ministry's undergrounds. This area is guarded - there is a high risk of getting detected. If you haven't got a UDL ID card yet, this is your chance to find it. This way you will avoid trouble.
However, before that happens, check the coded terminal located in the room to the left of the entrance. If you hack it, you can read Caroline's message about a man named Theodore.
Next, reahc the upper floor and talk to the author of the message. If you use the information written in it, the woman will help you enter the lab. Follow her and wait until the guard lets you in. You can now reach the bottom without any problems.
Unfortunately, the doctor's help won't work on the lower floor. If you want to avoid stealth, go to the first door on the right of the elevator. There, you can find a card that will allow you to camouflage. With its help, you will be able to go through the lab without any problems.
When you reach the room with Dimethyl Sulfoxide, the first thing you should do is to head to the terminal and get 26,371% of the substance. Then, take the tank and leave the building.
Finally, go to Phineas in his laboratory.