Priority Mars
Admiral Hackett ordered the Normandy to Mars to locate new Prothean data that could help defeat the Reapers, but the archives on Mars are not responding. Investigate the dig site and find the Prothean data.

Acquisition Edit

Prerequisite: Prologue: Earth

This mission is automatically acquired and started after the Prologue's completion.

Preparation Edit

Upon starting this mission, Shepard will automatically be equipped with a new weapon, based on class: The M-4 Shuriken for Adepts and Engineers; the M-23 Katana for Soldiers, Vanguards, and Sentinels; or the M-92 Mantis for Infiltrators. Note that whichever weapon Shepard is given will not appear during the mission as a pickup. Your first chance to customize your weapons loadout occurs the first time you find a weapon pickup, but mods cannot be attached until you reach a weapon bench.

James Vega will only be your squadmate for the first enemy encounters, so use up his grenade supply freely.

When James leaves your party, any "Squad Incendiary Ammo" bonus that you (and your third squadmate) have received from him will remain active unless/until you activate a different ammo power, or re-equip your squad by picking up a new weapon or at a weapon bench.

This mission features the first appearances of a major enemy faction's units and you'll be seeing them again in various places throughout the rest of the game. Counters and tactics you learn beating them here will be largely applicable on future encounters.

Walkthrough Edit

Mars outpost 2186
Start by leveling up your squad, as prompted, then head down and jump through the gap in the fence. Pick up the M-92 Mantis to your immediate right and examine the body for some XP, and then continue on down the path.

There will be some Cerberus Assault Troopers ahead. The first group will be oblivious to your presence, and if you take a closer look they're executing civilians. You can take them by surprise, you have the higher ground, and they're all standing right next to each other. Make sure to position yourself and your squad in appropriate cover before engaging.

Another group of Troopers will be hiding behind the various vehicles parked further ahead, attempting to ambush you. Be wary as they will reveal themselves from multiple directions. Take them out accordingly, then move into the compound. Note: Tagging the elevator button inside the entrance of the compound will instantly trigger the progression cutscene, bypassing any remaining enemies.

Into the Facility Edit

Mars - liara pointing (mission)
Handle the long cutscene talking with either Kaidan or Ashley about your loyalties; paragon/renegade points are available here. Liara also enters the game at this point. Shepard will send James back and you will gain Liara as a squadmate for the rest of the mission.

The cutscene will lead straight into a combat scenario, so be ready. You'll also get to command Liara's biotic powers. Kill off the guards that come through. If you want to save ammo, simply spamming Singularity several times without taking any other action is usually enough to eliminate all the enemies. Detonating them with secondary powers will expedite the process.

Pick up the med kit on the right (100XP) after finishing the battle. When you try to take the elevator up, you will discover that it has been sabotaged, so raise the vehicle lift, climb up the ramp to the left of the vehicle and jump across.

Head around to the right and open the door, then learn how to grab-kill a trooper from behind cover. Beware of the other enemies in the room whilst you attempt this, and expect an immediate melee fight and probably a grenade as soon as you do it. Tip: When the grenade arrives, sliding up the stairs to the right leaves you in a safer position than returning back to the left.

Mars - shuriken + AT gauntlets
Enter the next room and examine the datapad on the last row of chairs (75 XP). From here, enter the control room and examine the locker to pick up Ariake Technologies Gauntlets. Continue in a bit to pick up the M-4 Shuriken, and then another med kit (100 XP).

Cafeteria Edit

Now, use the security console to unlock one of the two doors. Head to the exposed Martian environment outside and down the ladder into a walkway. At the end of it, right before the ladder up is the Kassa Fabrication Chestplate.

Up the ladder is a suspiciously open airlock. Continue around inside. The lights are out, and you'll switch to flashlights so your vision will be reduced for a while. There's a datapad (75 XP) in the floor just before you descend the steps.

There are enemies in the cafeteria opposite you, but they cannot see you as your team will switch off your flashlights. You can grab-kill the closest enemy, hop over the wall and lay waste to the Troopers. Alternatively, you can simply shoot through the glass.

In the cafeteria is an SMG Scope upgrade. Hop over the wall and use the medical station on the right (150 XP). Access the environmental controls to open the next door and learn that the new doctor was the one who killed everyone off.

Fighting Through the Corridors Edit

Mars - headshot
Continue through the door and pick up the SMG Ultralight Materials and the datapad (75 XP) at the bottom of the stairs. You can then use the weapon bench on the right to change your loadout and apply the upgrades to Liara's weapons, and your own if you carry an SMG.

Up the stairs and through the door for another Cerberus wave. You'll now be facing Centurions and Guardians in addition to the normal Troopers. An Adept or Vanguard can use Pull to reliably remove the shields from the Guardians. Kaidan can use Reave, or Ashley can use Inferno Grenade, which will go through their shields. Liara's Singularity can also lift the enemy, but they must be standing still before she uses it, otherwise, it will only stagger them. They may not all come charging at you in which case you will have to move forward. Pick up the datapad (75 XP) on the right halfway up the corridor, then go around to the left.

With the exception of Guardians, the Cerberus troops throughout this hallway fight tend to be beating a retreat, so moving up when you can will assist them in deciding to back up even further. Eventually they will retreat out of the section and seal the door behind them, so you don't necessarily have to kill every single enemy. In other words this is a good section to play relatively conservatively. When you turn left around the corner, you will be at a wide hatchway opening, and will need to pass through two additional similar hatchways before the remaining enemies will shout "fall back to the tram station" and retreat through the fourth such hatchway.

Next up you will find clean room sterilization controls. Look through the windows to see an orange barrier. Activate the console to move the barrier around the room. Wait until the barriers are maximally open before you deactivate the console. Enter the room to get a Sniper Rifle Extended Barrel, a Shotgun High Caliber Barrel, a med kit (100 XP), and a datapad (75 XP). Continue through the room and out the door on the far right side.

Autoturret and Tram Edit

Mars - turret run
If you do not already have one, around the corner to the right, you will find the M-23 Katana. Open the door to the next area, and come face-to-face with a huge ceiling mounted turret. Time to learn how to use extensive cover to avoid fire.

The turret targets you exclusively, so you don't have to worry about your squadmates getting ripped apart. Your squadmates move once you move, and once you move the turret takes a split-second to fire at you. Don't try skipping cover placements as you will not be fast enough to evade the turret's sight, and don't even try cloaking your way out as the turret can detect you. Just follow the on-screen prompts, you'll reach the other side eventually. At that point the turret deactivates permanently.

Tip: The Cerberus soldiers in the control room will not come out. They are also passive prior to Shepard getting behind it. Any time before the last piece of cover, an Engineer can spawn a Combat Drone inside the control room and none of the soldiers will react. Wait long enough and the one Drone will kill all the Cerberus soldiers.

Once you've dodged and rolled your way past the turret, open the door and kill off the Cerberus operatives. Pick up the med kit (100 XP) on the right, the datapad further up the room (75 XP), and the Sniper Rifle Concentration Mod. Be sure to fill up on ammo. Finally go and use the auto-turret controls. A short cutscene will reveal that Cerberus has implanted its people with Reaper technology.

You will get a brief tutorial on squad control in the next area. Use superior tactics (or superior firepower if that's not your thing) to your advantage and kill the enemies exiting the cable car. Tip: Before you activate the cable car, return to the control room and refill your ammo from the cartridges there, which will have respawned. This will be your last easy opportunity to pick up ammo for some time.

Get on the cable car and turn it on. Near the other end there will be an explosion: your car will get stuck and a Cerberus one will start moving toward you. Liara's Singularity can pull operatives out of the car and hang them over the air to fall to their death. Jump across to the other car once they are dead - or even before, if you like to fight at close quarters.

Tram Fight Edit

Mars - peripheral vision
Activate the other car and prepare for a fight as you arrive in the station: Troopers and Centurions en masse against you and your team.

This is the last big fight of the mission, and it's also very much the toughest you'll have faced so far in the game. Feel free to unleash everything you got, even grenades. Beware of grenades thrown at you, however, your companions will not always move out of the way. It's usually safest to stay in the car during most of this fight because the cover offered outside of it is easily flanked, and if you have a reasonably long-ranged weapon the pillar at the rear of the car gives good visibility and is seldom reached by the constant stream of grenades. When the first wave starts to die down, a second one will stream in from the back, this time with Guardians.

After the fight, pick up the M-15 Vindicator on the far left, investigate the medical station in the center of the room (150 XP), and the Shotgun Shredder Mod on the far right.

Warning: If you are playing a New Game Plus and carrying the M-77 Paladin, Scorpion, Acolyte, or Executioner Pistol, it is recommended that you switch them out or ensure that you have a faster-firing weapon at this time. The damage output and/or fire rate of these weapons are low enough that the final moments of the mission can become almost impossible to complete.

Once you've finalized your loadout to your satisfaction, open the door at the end of the room.

Prothean Archives Chase Edit

Mars - Prothean Archives
You find yourself at a large circular chamber. While the Virmire survivor inspects the far side of the room, you and Liara will come closer to the Prothean artifacts at the chamber's center. A hologram terminal will activate nearby, and the Illusive Man appears. A discussion with him occurs during which you can apply a Charm or Intimidate dialogue option depending on your Paragon/Renegade score. At the end of the conversation Ashley/Kaidan discovers Dr. Eva Coré, the Cerberus mole, and a chase begins.

If she gets more than 40m away you will fail the mission, so stay close. It's also not worth trying to attack her, as she has an exceptionally high shield recharge rate, and even if you do somehow bring down her shields she will merely use Shield Recharge to instantly bring them back to full strength.

Further along the chase Cerberus Troopers on a shuttle will arrive on the scene and attempt to harass you. Given the urgency of the situation, ignore them. They won't damage you significantly. If you can't resist, though, a Singularity from Liara can take care of them.

At the end of the chase Eva jumps into the shuttle and is about to escape when James crashes his shuttle straight into hers. Your squadmates will pick each other up after the crash, but Eva jumps out of her burning shuttle, her organic disguise destroyed, and severely injures Ashley/Kaidan.

After this Eva will begin running at the player in slow motion, and the player must shoot her. Shepard wields a pistol during this sequence by default, and certain slow-firing pistols (i.e., the M-77 Paladin, Scorpion, Acolyte, or Executioner Pistol) can make this sequence difficult, if not impossible to complete. If you are carrying one of these weapons, consider shooting from the hip instead of scoping, or switching to a different weapon, though this will obviously take time.

After Eva has been shot down, Shepard will choose to bring the body (now known to be an infiltration unit) on board the Normandy and will head straight to the Citadel for the next mission.

Enemies Edit

Datapads Edit

From: Cameron Harrison
To: ExoGeni Corporation

Miss Mika,

Thank you for your kind offer of "new" and "cutting-edge" technology. As with every other offer you've made, we're going to have to decline. Our proprietary rights experts have gone over your contracts (again) and found them lacking (again) and, in short, we're not interested.

Please don't contact us anymore with your "generous" offers.

C. Harrison

From: Sho D'hen
To: Cameron Harrison


Who the hell is that woman messing in my files? GET HER OUT OF HERE! I won't have my system messed up by some wannabe "expert" who'll be gone next week! Damn strangers who think they know it all but don't care about what we're really trying to achieve here. Dr. Eva. Seriously? Don't you remember what happened LAST TIME?


From: Amelia Hatterson
To: Mike O'Sullivan

Hey stupidhead!

I won't ask how you're doing, since I hear you guys are propagating germs in the shape of a cold down there in storage. Look, I know your prothean doodads are fascinating and all, but you guys have got to stop burning the midnight oil and keep regular sleeping hours, honestly! Anyway, I forwarded your latest findings to HQ on Earth and SOMEONE IS DEPRESSURIZING THE AREA WARN SECURI

From: Faiza Haikal Tkele
To: Sandoval Fletcher

Yeah, I know. Two external specialists in the same week is a bit insane. But Hudson, I've heard about the asari before! She's really well known, and she's done some amazing research on the Protheans. I don't know zip about that Dr. Eva chick, but Liara T'Soni? She's the real thing. I'm attaching some of her advanced papers on Prothean culture. Read 'em. You'll be a believer too when you're done.

I can't wait until they introduce her to people. This is so exciting!


Personal Notes: S. Esparza

We haven't been able to decipher much--if any--of the language yet, but the visual documentation gives us some idea as to what they were studying. Namely, us. They seemed particularly interested in early humanity's evolutionary process, judging by the way they organized their files and highlighted specific occasions. It seems a bit fantastic to write this, but everything indicates that they seemed to be trying to chart the curve of humanity's intellectual progression.

Research Notes: J. Tasmen

The last location seems to have run dry, but judging from the communications system layout and the backup power supplies equipped by the first Prothean research base we discovered, we think a secondary base may be located deeper underground. We're going to need permission from the Powers That Be to excavate further, but considering the recent renewal in enthusiasm for the work we're doing here, I don't think clearance will be an issue.

Mass Effect 3 Navigation
← Previous Mission Mission Index Next Mission →
Prologue: Earth Missions Priority: The Citadel I
Community content is available under CC-BY-SA unless otherwise noted.