In the The Outer Worlds, the final quest of Phineas’ questline is The City and The Stars. You get it automatically by completing Radio Free Monarch. This walkthrough will guide you through this quest.
The Outer Worlds The City and The Stars
First you need to head to Byzantium and talk with Ellie by the exit door. Then head down the ramp outside the ship and talk with Carmen Imagawa.
She guides you on what to do next and tells you to get a security key from one of the guards who is at the tavern. She can also share information about Byzantium and why she joined the movement.
Enter the city via the nearby lift and you’ll encounter Maverick Johnston. He offers you the quest At Central. Head to the pub and enter Billingsly’s House of Inebriation to talk with Mr. Billingsly.
The guard Mayfield is already super drink so you can get him to talk about the key pretty easily. Give him the Spectrum Vodka until he’s so hammered that he needs to lie down. You’ll then have your opportunity to loot the key and get out of there.
This key unlocks the minister’s residence, so head there and talk to the guard by the door. He’s not going to allow you to go inside but mentions that he’s expecting a delivery. This gives you an opportunity so head to the office near where Giles Molina is and get the package.
For the next portion of the quest, enter the Halcyon Parcel Service shop and use a lockpick to break into the storage room. Once you bring back the package to the main door, you can walk right in.
You’ll find Minister Clarke on the second floor so go talk to him. Once you bring up the dimethyl sulfoxide, he’ll tell you that he has been under house arrest for years and point you to the chairman’s office in HHC headquarters.
You can access it via the maintenance tunnel access point that you can enter via the access card the Minister gives you. It will take you to the executive suite. However, if you’ve completed Balance Due then you already have access to the HHC building and don’t need to use the tunnels. You could also just bribe the guard for 2000 bits.
Speak with Guard Bachmayer and then take the lift. Once you’re where Percival Platt is, head left and use the Access card to open the door. Get the key and then head back out to talk to Percival Platt. You can Lie to him so that he heads back to his desk and then take the elevator down.
Open the locked door on your left with the key to open it to enter the Ministry of Accuracy and Morale. You have to go to the restricted door to the right. If you have the Key, you can try using conversation to get past the guard or you can try going around him.
If you have Hack (47) then you can get into a terminal and find out that Caroline and Theodore from the Ministry have conflict with each other.
Go to the second floor and meet up with Caroline Endecott. You can inquire about Theodore Isaacs and lie so that she unlocks the lab for you. You still need an ID so use your lockpick to open a door in the area that Holte is guarding.
Talk to the guard so that you can avoid a fight and then pick up the ID card that is in the center locker. Collect it and then close the door behind you before you take the elevator down.
Go through the labs to the waypoint and you can get the chemical in an empty canister. Collect a small amount of the Dimethyl Sulfoxide for Phineas to work with. If you didn’t betray him to The Board: then Sophia Akande will message you when you board The Unreliable. She will try to convince you to turn Phineas in and if you stay impartial, you will get the quest Long Distance.
Go to Phineas and he’ll reveal that he was aware of the starvation problem, and wanted colonists to be able to solve the problem once he unfreezes The Hope. If you have a Science and Engineer skill of more than 40, then you can suggest a micro-jump within the system to get The Hope.
Completing this quest unlocks the Kept Secret but not Forgotten quest, grants you 142000 XP, unlocks access to The Hope but also reduces your reputation with The Board.