Mass Effect 3 Walkthrough

Mass Effect 3 Walkthrough Act 3 – Priority: Cerberus Headquarters

Mass Effect 3 Cerberus Headquarters is the first mission of the third and final ME 3 act.

Priority: Cerberus Headquarters is a mission that must be completed in order to access Priority: Earth. It follows the events of the previous missions, and brings Shepard and his crew to Cronos Station.

The following Mass Effect 3 guide explains how to beat Cerberus Headquarters while playing Mass Effect 3.

The guide reveals some of the most important points of interest where players will find new weapons and new armor upgrades.

Additionally, our Mass Effect 3 game guide also offers tips and tricks that can be used during the battle with the final boss featured in this mission.


“The Illusive Man’s headquarters have been located, and the Alliance is prepared to attack to recover the Prothean VI that holds the key to the Catalyst. Once the attack is launched, the Alliance will be fully committed to the final fight against the Reapers. Assault the base when ready.”


55.000 Credits, Reputation


To begin Priority: Cerberus Headquarters and the final Mass Effect 3 act use the Galaxy Map to find Horsehead Nebula, and travel to Anadius. The Illusive Man’s base is on Cronos Station. When you are ready, launch the attack, by entering the orbit and docking on the station.

The mission’s first cutscene shows a dialogue with Admiral Hackett. At this point you will have to decide if you wish to continue your attack or not.

NOTE: If you continue, you won’t be able to return to the Citadel. The final missions featured in the last act of the game, are linked together. Make sure you have completed all side-quests, Citadel missions and N7 missions.

The conversation with Hackett is followed by a discussion with the romanceable character, and the third dream sequence.

This sequence is similar to those you have completed before. Shepard must chase the kid in the forest. Follow the boy and watch the next cutscene. Continue to discuss with the members of your team, and then select your crew (EDI is a default member for this mission).

Equip your favorite weapons, and don’t forget to spend progress points to improve your team’s powers and skills.

While the Alliance attacks the Cronos Station outside, you will enter the base through a hangar. Keep in mind that you are inside the main facility controlled by Cerberus, so expect multiple enemies. You will be attacked as soon as you land, by Cerberus Troopers, Nemesis and an Atlas mech.

Stay in cover and kill the Nemesis first, followed by the Atlas and the Cerberus Troopers. After you clear the area, you will be asked to reach a console and stop Cerberus from ventilating the hangar. It’s important to know that this objective must be completed before the time runs out.

So, make sure you locate the ladder on the left side of the hangar. When you reach the second floor, turn right and activate the console.

After you secure the hangar, more Cerberus troops will attack your position. Your next objective is to escape the hangar. Follow the corridor on the top floor until you reach another green-panel door.

Behind it, activate the Rotation Controls console and continue to advance. On the right side of the corridor, is a ladder which allows you to reach the bottom floor, while in front of you is another green-panel door.

If you open it, you will enter a small chamber and inside it, on some crates you will find a PDA (5.000 Credits).

Turn back and use the ladder to descend, and near the ladder, to the right, you will see a red console. Use it to release the clamps that keep the shuttle on the ground, then you will be able to create an exit point.

Destroy the Atlas mech and the Cerberus that attack you (you can use one of the mechs in the hangar), and then investigate the exit point you have created. On the left side, in a darker area you will find the M-37 Falcon.  Pick it up then examine the yellow-panel door on the left side.

In the next area, follow the ladder to reach a lower level inside the facility and advance towards the objective marked on your HUD. Kill all Cerberus and when you reach the other side of the hall you will see a ladder which allows you to go up. While facing the ladder, look behind it and you should see some red pipes.

Next to them, to the right, is a Terminal you can salvage for 5000 Credits and a Medical Station.

Next, follow the ladder up and you will trigger a cutscene. After the cutscene access all three logs and talk to one of your crew-members. EDI will eventually open the next door, but don’t leave the room without the Serrice Council Greaves, located on a box in the central area.

Continue to push forward towards the Central Lab, but stay alert because you will have to defeat multiple Cerberus Engineers. When you reach the next ladder, go up then turn left to access a new Cerberus Video Log.

Play all three entries, and then proceed through the door EDI opens for you. In the next chamber, check the right side for a PDA (on a desk) and the left side for a Medical Station.

Push forward and on the left side of the hallway you will see a hole in the floor; however don’t advance without checking the two rooms located at the end of the passage. In the first room you will find a Med Kit (left wall) and the Delumcore Overlay (central area).

In the second room, near a console is another Cerberus Video Log. Now, turn back and go through the tunnel you saw earlier.

In the next area you will have to follow a series of suspended platforms and ladders that will take you to the Cerberus Lab. Make sure you are ready to fight waves of enemies, and use the panels on the right and left side of the platforms as cover points. Advance slowly, and eventually you will reach another green-panel door. Your objective changes as soon as you enter the next room. You will be asked to Activate Protean VI.

While advancing towards your objective, near a control panel located to the left, you will find a Med Kit and a PDA. On another desk (same side) is a Cerberus Video Log. Once you get the items, go through the door and follow the ramp up, to trigger a cutscene.

Talk to Illusive Man and Protean VI, and then get ready for a boss fight. This time you will have the chance to defeat Kai Leng; however don’t expect for him to go down without a proper fight.

The first thing you will have to do, when the fight starts is to escape him, by mashing B (on Xbox 360). During the next phase, you will notice that Leng regenerates his shield, by destroying the ground to gain access to more energy.  Observe that when he recharges, the holes he creates can be used as cover points.

Make sure you use them to protect yourself from the Cerberus troops that spawn. Take them out, first, and then take care of Kai Leng. You can also focus on the boss if you wish, but it’s risky.

Use the powers of your team to slow him down, and try to aim for Leng’s head. Fire-based powers can be useful, but they depend on how you leveled your character and your character’s class. After you defeat him, a new cutscene starts.

During this cutscene, Kai Leng will try to hit you from behind. Make sure you pull RT to finish him for good and to unlock the Executioner trophy/achievement.

Next, you will return to Normandy, and you will talk to Anderson. The final act of the game (Priority: Earth) is now unlocked.

Mass Effect 3 Walkthrough
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