“Keeping the Peace” is one of the first side missions that you get and the one that starts you off with the United Colonies faction in Starfield.
The UC Vanguard is looking to add more officers to its force. This is an opportunity for you to join the UC Security Force, but you need to first pass the job interview.
How to unlock the “Keeping the Peace” mission
There are no prerequisites here to know about. After landing on Jemison, enter the UC Security Office to the right and speak with Sergeant Yumi to start the Keeping the Peace side mission.
If you still have not received a prompt to talk to Sergeant Yumi, you need to go near and listen to some of the people talking about Sergeant Yumi inside the UC Vanguard headquarters.
How to complete “Keeping the Peace” in Starfield
While speaking with Sergeant Yumi, tell him that you are looking for a “job” in New Atlantis, specifically in the United Colonies security group.
He will instantly start taking your interview where you need to answer several questions. You can answer them in any way you like. The outcome will remain the same in all scenarios.
Once done, Sergeant Yumi will send you off to find and speak with Agent Plato. He apparently has a job for us.
Find Agent Plato in the MAST building
The quest marker will take you to a transit car near the UC Security building that you can ride to reach the MAST District. The journey from here needs to be done on foot.
After reaching the MAST District, head up the ramp and then turn around to see the main MAST building ahead. There is an elevator here that you need to take to the “Defense Research / Health and Human Services / Aegis” floor — quite a mouthful.
Spot the “Aegis” door on your right and enter to find Agent Plato inside. Speak with him about the package and he will give you all the necessary details you need to complete the Keeping the Peace mission in Starfield.
Recover the package
Agent Plato’s package is located on a bench in the Starport area of New Atlantis. From the MAST building, take the elevator to the NAT Station. You need to take the transit car again but this time to the Spaceport.
When you arrive at the Spaceport, you will see the Galbank ATM on your right. Go over there and recover the package from under one of the benches here. Do not worry, the quest marker will help you find the right bench.

Hand over the package to Sergeant Yumi
Once you have retrieved the package, you need to go back to the UC Security Office where the side mission first began. Speak with Sergeant Yumi and hand over the retrieved package. This act of yours will bring the side mission to an end.
After a short period of time, one of the UC security officers will come to you to tell you that Sergeant Yumi again wants to speak with you. Once you start your conversation with her, a new side mission will be given to you which is A Break at Dawn.
Starfield – Keeping the Peace mission rewards
On your successful completion of the Keeping the Peace side mission in Starfield, you will be able to get the rewards of 4,300 Credits and 100 EXP.