Mass Effect 3 Guide: How to Complete Citadel: Cerberus Retribution

If you’re working through Mass Effect 3 and want a thorough walkthrough for the Citadel: Cerberus Retribution side job, this guide breaks down everything you need—from where to locate the relevant items to how to handle each fight and what decision paths matter for your playthrough.

Looking for a specific section? Use the jump points below to get where you want faster.

  • Mission Stats
  • Travel to Widow
  • Overhear the Arguing Citizens
  • Meet Captain Aaron Sommers

Mission Stats

Video Guide

Mission Rewards

  • Mission Experience: 210 XP
  • Mission Credits: 5,000 credits

Travel to Widow

  • Prerequisite: Complete “Priority: The Citadel 2”
  • Location: Serpent Nebula – Widow – Citadel – Presidium Commons – C-Sec Outpost

You unlock this side mission only after finishing “Priority: The Citadel 2”. That completion refreshes the Citadel and brings a fresh set of side missions into rotation, including this one. The Citadel serves as the galaxy’s central hub, and it will always be shown in the western portion of the Milky Way map.

Overhear the Arguing Citizens

The start of this side job is a little unconventional. Once “Priority: The Citadel 2” is done, head to the staircase that links the Apartments area to the C-Sec Outpost (on the map screen, the outpost is marked with a 5). At the corner of that staircase, along the western wall of the outpost, you’ll find two humans in conversation. They’re discussing someone they believe is a traitor—specifically, how that person killed their respective romantic partners.

When you attempt to speak with them, a man broadcasting over a radio claims he’s ready in the C-Sec Outpost. He asks the two citizens to draw C-Sec away so he can carry out the killing. Shepard responds firmly, ordering the pair not to cooperate with the caller.

Meet Captain Aaron Sommers

After you begin the side mission, enter the C-Sec Outpost and look left. On the couches, you’ll spot a man in a black-and-burgundy outfit named Captain Aaron Sommers.

Sommers tells you that his target is a C-Sec officer who is also a former member of the Alliance military. According to him, the officer assisted Cerberus during their recent coup attempt. Sommers explains that the man secured a plea deal by handing over Cerberus intel in exchange for a shorter sentence, but Sommers believes the punishment is far too lenient—and he intends to execute the captive himself.

If you want extra clarity on what got the target into custody, you can ask, “Why is murder justified?” Then pick one of the options below:

  • Choose “You’re better than this Charm” to argue that Sommers’ actions would be disrespecting the uniform as well. This choice grants +5 Paragon Points.
  • Choose “Walk away” to state that Sommers would be arrested for the murder. That line of reasoning is enough to shut down the plan, and you’ll earn +5 Paragon Points.
  • Choose the “Let me do it legally” Intimidate option to use your Spectre status to authorize Sommers to kill the man in custody under legal cover. This choice awards +5 Renegade Points.
  • Choose “Go ahead” to ignore the scheme and allow Sommers to proceed. You’ll earn +5 Renegade Points.

No matter which option you select, completing the side mission still pays out 210 XP and 5,000 credits.

Want more Mass Effect 3 help? The guide also points players toward these additional pages:

  • Legendary Edition Changes
  • How-To Guides
  • Key Choices and Consequences
  • Romance Guide
  • Walkthrough
  • Side Missions

Up Next: Citadel: Cerberus Turian Poison

Top Guide Sections

  • Legendary Edition Changes
  • Game Basics
  • Tips and Tricks
  • How-To Guides

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