UNC: Depot Sigma-23


Quest Type



Unidentified Space Facility, Gorgon System

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UNC: Listening Post Alpha
UNC: Listening Post Theta

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Experience Points

UNC: Depot Sigma-23 is an Assignment in Mass Effect. UNC: Depot Sigma-23 is about a Rachni outbreak in the Gorgon System. Assignments are secondary quests in Mass Effect, that are not mandatory to progress the game's story, but provide context and flavor by meeting interesting NPCs of all kind of Races, granting additional experience, and letting the player visit extraordinary and unique planets.


UNC: Depot Sigma-23 Walkthrough

After learning about the Rachni outbreak after an automated supply delivery, travel to the Gorgon system in the Argos Rho cluster. Board the Unidentified Space Facility. There are no Enemies at the entryway, so head to the main hold of the ship.

You will find a single Rachni Soldier, located on your left once you enter the room, and 7 Rachni Workers. Clear the Rachni Soldier first as it is the greatest threat and then focus on the Workers. Once the hostiles are down, turn around to hack the two Weapons lockers.  After that, keep moving forward.

On your way, you will find more containers. First a secure crate that requires Average Decryption, a wetware kit hidden in an alcove, a technician kit, before the door to the forward section there is another locked crate that requires easy Decryption and around the corner, you will pick up an upgrade kit. Head through the door.

Head to your right to obtain a medical station that requires easy Decryption, a crate, 2 storage lockers and an upgrade kit. You won't find anything at the cockpit.  Now head to the left module. There you will find a terminal with data logs by Major Elena Flores. Listen to the logs to learn about what happened here.

  • The first log describes the station as an operational one, stating that they will be adding barracks and stocking munitions. 
  • The second entry describes the arrival of the package and how different these are supposed to be. Flores documents a plan to test the Rachni on some local Pirates.
  • The third and final entry, describes that the Rachni have escaped. They accessed freighters going to random destinations. Flores tells someone referred to as General,  to "Screw the Rachni" and destroy the station.

Next to the terminal you will find some demo charges, ONCE you access the terminal, you will have 70 SECONDS to get back to the Normandy in one piece. Before preparing to set the charges, make sure you are not leaving anything behind. Once you do, set the charges and run!

At the moment you arm the charges, more Rachni will spawn to block your access back to the Normandy. Five Rachni Workers and a Rachni Soldier will be waiting outside the door. Send in your squadmates first, and then follow them. Take the Rachni as fast as you can, and head to the Normandy. Once you reach the Normandy, keep going until you leave  the planet because the clock doesn't stop, and only once you do, the Assignment will be labeled as completed.


How to unlock UNC: Depot Sigma-23


Enemies found on UNC: Depot Sigma-23


UNC: Depot Sigma-23 Rewards

  • N/A


UNC: Depot Sigma-23 Notes & Tips

  • Notes & tips go here


Assignments in Mass Effect
A Person of Interest  ♦  Citadel: Asari Consort  ♦  Citadel: Doctor Michel  ♦  Citadel: Family Matter  ♦  Citadel: Homecoming  ♦  Citadel: I Remember Me  ♦  Citadel: Jahleed's Fears  ♦  Citadel: Negotiator's Request  ♦  Citadel: Old Friends  ♦  Citadel: Old, Unhappy, Far-off Things  ♦  Citadel: Our Own Worst Enemy  ♦  Citadel: Planting a Bug  ♦  Citadel: Presidium Prophet  ♦  Citadel: Reporter's Request  ♦  Citadel: Rita's Sister  ♦  Citadel: Scan the Keepers  ♦  Citadel: Schells the Gambler  ♦  Citadel: Signal Tracking  ♦  Citadel: Snap Inspection  ♦  Citadel: The Fan  ♦  Citadel: The Fourth Estate  ♦  Citadel: Xeltan's Complaint  ♦  Doctor at Risk  ♦  Feros: Data Recovery  ♦  Feros: Geth in the Tunnels  ♦  Feros: Power Cells  ♦  Feros: Varren Meat  ♦  Feros: Water Restoration  ♦  Garrus: Find Dr. Saleon  ♦  Geth Activities  ♦  Investigate Facility  ♦  Investigate Samples  ♦  Investigate Shipments  ♦  Mercenaries  ♦  Missing Person  ♦  Noveria: Espionage  ♦  Noveria: Smuggling  ♦  Pinnacle Station: Combat Missions  ♦  Pinnacle Station: Convoy  ♦  Pinnacle Station: Vidinos  ♦  Strange Transmission  ♦  Tali and the Geth  ♦  UNC: Asari Writings  ♦  UNC: Besieged Base  ♦  UNC: Cerberus  ♦  UNC: Derelict Freighter  ♦  UNC: Distress Call  ♦  UNC: Hades' Dogs  ♦  UNC: Hostage  ♦  UNC: Listening Post Alpha  ♦  UNC: Listening Post Theta  ♦  UNC: Locate Signs of Battle  ♦  UNC: Lost Freighter  ♦  UNC: Lost Module  ♦  UNC: Missing Marines  ♦  UNC: Missing Survey Team  ♦  UNC: Prothean Data Discs  ♦  UNC: Rogue VI  ♦  UNC: The Negotiation  ♦  UNC: Turian Insignias  ♦  UNC: Valuable Minerals  ♦  Virmire: Assisting Kirrahe's Team  ♦  Virmire: Wrex and the Genophage  ♦  Wrex: Family Armor  ♦  X57: Avoid the Blasting Caps  ♦  X57: Bring down the Sky  ♦  X57: Missing Engineers

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