Liara T'Soni, an asari archeologist famed for her knowledge of the Protheans, is being sought by Saren. Her last known location was somewhere in the Artemis Tau cluster.

Acquisition[edit | edit source]

Prerequisite: Citadel: Expose Saren

This mission is acquired after Shepard is given Spectre status and Shepard reports to Dock 422. Udina will say that Anderson is stepping down as the commanding officer of the SSV Normandy and that the ship is now commanded by Shepard.

When asking Captain Anderson about the mission, he will say that he has never been to the Artemis Tau Cluster so he wouldn’t know. He says to look for the world with the Prothean ruins.

Go to Therum in the Knossos system of the Artemis Tau Cluster.

Preparation[edit | edit source]

This is recommended to be your first core world mission as it will recruit your last squadmate. If you choose to delay, an alternative first meeting scenario will play out in this mission, detailed below. Choosing to delay this mission significantly results in loss of character interaction, a valuable biotic teammate for much of the story, and a romance option, all of which are excellent incentives to do this mission right off the bat.

You will be facing mostly geth all the way, so the usual tech talents will be helpful. Tali's AI Hacking Ability, or Shepard's, if Shepard is an Engineer, can be particularly useful in this mission.

As per standard procedure with geth, have a good anti-jamming mod ready. This is a mission where all your weapons will be useful in particular instances, and pay close attention lest they cause your weapons to prematurely overheat.

If you’re playing on Insanity and especially if you have a low level character and this is the first planet you go to after leaving the Citadel, keep in mind that you will be facing a particularly challenging opponent at the end. Strongly consider having the Lift, Neural Shock, Throw, and/or Stasis talents in your arsenal. Be sure to have armor configurations favoring hardening, damage protection, and/or physics threshold attributes.

Walkthrough[edit | edit source]

Arrival On Therum[edit | edit source]

Prothean dig site on Therum

The Normandy swoops down and drops the Mako on the planet. Therum is a volcanically active world. The Mako cannot survive even brief contact with the molten lava. Save your game here as a start save and move up. Joker will come over the radio saying that he is picking up some readings, “like off the damn charts” a few clicks, kilometers, north of the drop zone. Move up and around the path until you hear a Geth Dropship overhead. The dropship will deposit two Geth Armatures for you to fight.

Mako Tips: Remember that every kill made from outside the Mako gives more experience than a kill from inside the Mako. Also, the Armatures only target the very front of the Mako when they fire, so turning 90 degrees from them and rocking back and forth is an excellent way to avoid most of their fire and keep your shield intact.

Another strategy is hitting the Armatures with the Mako and make them fall in the lava, which is an instant kill and gives the player the same XP as killing them on foot, but this requires timing to work.

Once both Armatures are down get back in the Mako and continue up the road. This is a good save point.

Industrial Outpost[edit | edit source]

After heading up the road a little, you will make a left turn and you will come under fire from three turrets outside an outpost. Depending on your squad makeup each will offer unique dialogue. Usually the first one to speak will say that a frontal attack is suicide, the other will say that there must be another way around. They're hinting that killing these three turrets is optional, so it's up to you whether you want to fight them for the extra experience. Meanwhile the turnoff currently to your right is your way forward when you're ready to proceed.

Down the narrow turnoff you will find another single turret. Keep moving while you take it down. Then save your game before moving forward, as the upcoming fight can be difficult.

Insanity Tip: On a high difficulty level where survival is at a premium, simply do not exit the Mako. The upcoming mass of geth is easily blown to kingdom come with your heavy guns. You will not receive optimum experience points if you do this, although as usual you can quickly exit the Mako to put the final killing blow onto a tasty enemy to collect full reward.

Inside the outpost, or sometimes boiling out from it, are some Geth Destroyers, Geth Troopers, Geth Rocket Troopers, Geth Shock Troopers, and one Geth Juggernaut. There are also some explosive materials around the camp, so use them to your advantage. Use the path to backpedal if you need to but to get the most experience you need to take out all of these enemies on foot. Use your powers to take out the geth and above all keep moving to stay within cover. Using the Mako for cover is not recommended, because it will continue to take damage whenever it is hit. If the Mako appears “on fire” it has been completely damaged, so do not re-enter until all combat is over because even a single point of damage will destroy it.

Once the remaining enemies are down reenter the Mako and drive it into the outpost. There are still two geth remaining, one inside either gatehouse. To your left as you enter the compound, you'll see the back of the original gates. Head into the building on the right-hand side of the gate. Move up slowly, send in your squad first to take it out since the geth inside is rocket armed and can one-shot you on higher difficulty levels. Once it’s down grab the upgrade kit in the building. You can open the compound gate if you wish, though if you didn't take out the original three turrets they'll now be able to attack into the compound.

When you exit the gatehouse, move to the gatehouse on the other side of the now lowered gate to find an upgrade kit. You can also explore the industrial structures to the left to find two crates. Now get back in the Mako and head to the gates on the far side of the compound. To your right you'll find a crate for decryption, but the building on the right is empty. The building on the left has the gate controls and another geth. Follow the same routine, send in the squad first to lure it out, then fill it full of holes. Once done, open the weapons locker, and open the gates allowing you to continue.

To The Ruins[edit | edit source]

Save your game before leaving. Once you leave you will come under fire from another Armature further along the path. Follow the same tactics as before to earn max exp. During this fight there will be another Armature further along the path that will be firing the whole time. When you advance far enough, two more will begin firing from across the lava pool to the left. Use the same tactics for all of them. Once you get past the two Armatures save your game because the next section features a powerful foe, a Geth Colossus.

When you get close enough you will come under attack by Geth Troopers and Geth Rocket Troopers. Take these out on foot for more exp or from the Mako for convenience and an increased chance of survival. Once you are clear of the geth infantry focus your attention on the Colossus. Turn your Mako perpendicular to the direction of the Colossus and rock from side to side to avoid its powerful shots. To get the most experience from the encounter, shoot it from the Mako until its health is a sliver, then exit the Mako and pound it with gunfire until it collapses. Then head up the ramp and into the tunnel.

Once you get through the tunnel, there will be two Rocket Troopers at the other end. These are a pushover on foot so get out and push them over. Then head through the open area to the next tunnel and enter it. There are two more Rocket Troopers about half way down the tunnel, and then just past the other end of the tunnel are some more Rocket Troopers and a Geth Trooper. Take them out any way you wish then proceed. You finally reach a point where the Mako can’t get past but you have two options here:

  • Option 1: Look at the Mako's radar screen to get an idea of how geth forces are placed as your personal radar will be subjected to jamming once you disembark. Exit the Mako and proceed on foot.
  • Option 2: Believe it or not, you can actually squeeze the Mako through that narrow slit[1][2][3]. Approach the slit slowly, head-on. After the nose of the Mako comes in contact with the walls of the slit, push into it full throttle. After a few minutes of wiggling side-to-side at full throttle, you should be able to squeeze through into the area behind the slit.

Bringing the Mako will make things easier and will just about guarantee survival but will give you less experience so make your choice. Even with the small delicate geth you will find in here you can always soften them up with the Mako machine gun and then exit to execute them for maximum exp. Note: If you ride the Mako all the way up to the battle with the Armature, the geth in that battle will just stand there doing nothing[4].

Beyond The Rock Barrier[edit | edit source]

After you proceed, the next area is filled with geth. Troopers, Rocket Troopers, and Shock Troopers will give you and the squad a warm reception. Use the large rocks that are around and take them out. On higher difficulties the geth will deploy shield barriers so you will have to shoot through them, but they like to run around them, so usually just wait. Once all the geth in this area are down, save your game, really save, before moving on.

When walking around the bend watch out for a targeting laser, as a Geth Sniper is on a tower in the next area and has full view of the bend. Find cover for you and your team and begin systematically eliminating the geth in the basin. Watch for the Rocket Troopers in this area, especially if Shepard is in the front cover. Their splash damage can sometimes kill you. The sniper makes this area difficult. Best to use a Throw or Singularity directed at the tower as that will usually send the sniper falling to its death. Also shooting at it with Overkill, Marksman, or Assassination will work too. If necessary you can send the squad ahead to "take one for the team" and then once the Sniper's Assassination beam fires come around the corner yourself and quickly knock it out.

Once the sniper is down move your squadmates into the basin and to the first large rock that is in the basin. That provides them with cover and if you keep Shepard on the hill, then you have the height and once all the geth fall head up the road an up to the next area. You can actually kill the geth that are hiding behind the barriers before you reach the upper level if they are aggressive or you stand back enough in the basin. Once all the geth in the area are down, head up the road, and Tip: SAVE YOUR GAME.

Ruins Exterior[edit | edit source]

Prothean Ruin Exterior

When you get close enough to the mine, a cutscene will play showing Shepard and the squad heading towards the ruins. On a catwalk overlooking the site, a Geth Hopper will be hanging from the underside. When the squad gets nearer, it wakes up, looks at the squad, then hops around while the squad passes under it. Then a loud rumbling signals the arrival of a dropship. The squad turns and watches it as it proceeds to drop off more troops. The troops include two snipers and two shock troopers. There are two Geth Hoppers already around so you have six infantry troops. The final thing the dropship drops is an Armature. Now you have seven enemies: six infantry and one walking tank.

Once you regain control, move immediately to the left and have your squad take cover far to the left out of sight of the Armature – this will prevent them from being killed by the Armature which would deny you the use of their all-important abilities. Put Shepard behind the nearest crate to the left.

On lower difficulties you can focus on the Armature while your squadmates focus on the other infantry. Just watch out for the shock troopers and snipers because they will advance on your position down the middle. Take them out first if your squadmates don’t because if they get behind you, it won’t be pretty.

Insanity Tips: On Insanity you need to get rid of all the infantry before you can afford to engage the Armature – you just won’t be able to safely put enough damage on it while dodging sniper and rocket fire to keep it from continually regenerating its shield. Use your squadmates abilities to pick away at the geth – note that abilities like Throw and Lift are useful for making the hoppers stand still. Try to completely overwhelm each geth infantry one by one – Overload their shields and then concentrate fire, because they don’t have much health beneath those shields but the shields sure do like to recharge if given any respite. Conveniently they will try to come forward to “flank” you, but this will give you an easier angle of fire without exposing yourself so much to the Armature, and may bring your squadmates’ guns into play as well.

Just be careful when you lean out because an Armature’s pulse cannon is often capable of taking you down in one hit. Even splash damage can be lethal. So move to the left when it is preparing to fire then back once the pulse passes. Using Sabotage on the Armature will help keep its big gun quiet long enough to get some shots in. Keep your squadmates in cover because the second they move out they will be targeted by the Armature. Whenever you get the Armature's shields down, pound it with as much damage as you can, because that damage won't repair. Eventually the Armature will fall, so head into the ruin.

Prothean Ruin[edit | edit source]

Once you enter the ruin, head down the entrance tunnel. When the catwalk at the end comes into view, send your squadmates first because you will encounter a few Geth Shock Troopers and Geth Snipers. There are a few containment cells that can help thin out the numbers. Once they are down, head down the catwalk and eventually you reach a forcefield with no way to bypass it. So take the nearby elevator down and once it gets to the next level head off to the right to grab a med kit. Once you start heading towards the next elevator, take cover because three Geth Assault Drones will come up from below. Overload, Sabotage, AI Hacking, Stasis, and good, old fashioned gunfire will make short work of them. Once they are destroyed, head to the next elevator.

Note: The Geth Drones shouldn't be too much trouble, but an alternative tactic involves rushing past them and activating the elevator, which ends any further combat. Use your squad's talents to distract or suppress the drones if you try this.

This elevator has a problem and it starts to short circuit as you go further down. Once the elevator screeches to a halt, exit it and go down the broken platforms. Behind this forcefield is someone. You can initiate a conversation with her once you get close enough. She will ask who you are and you can answer her questions as you like. You will discover that this is indeed who you are searching for. Liara will say that she is trapped in a Prothean security device when she tried to protect herself from the geth, but she must have pressed something she wasn’t supposed to. She will ask for your assistance to get out. You can ask about Benezia, but she will say that she hasn’t talked to her mother in years. Once you have all the information you need, she will say that the console next to her will disable the field. She will say that she can’t think of a way past the barriers so you have to go hunting for a way past the barriers. Liara also warns that there are more geth being led by a krogan.

Once you regain control turn around and head down the catwalks to the left. In the pit below are some more geth. Specifically a sniper, two troopers, and two shock troopers. Insanity Tip: You won’t have a problem here unless you take a rocket in the face or get one-shotted by the sniper. The sniper often stays way back where he has an excellent line of sight to get some nasty tricksy shots in, so be careful when you walk out from behind a rock. Consider sending your squad ahead to flush him out.

Once all these are down head to the back of the pit to recover a weapons locker and a storage locker from the tents in the back, there will be only one in each tent. Once you have the loot head over to the terminal next to the mining laser and enter the code.

  • On the Xbox 360 the code is “A”, “X”, “B”, “Y”
  • On the PC the solution is randomly generated each time a saved game is loaded.
  • On the PS3 the code is "X", "Square", "Circle", "Triangle"
Liara in the bubble

Once you enter the code, a short cutscene will play showing the laser burrowing into the ground and creating a tunnel to allow you to get past the barrier curtains. Go down into the tunnel, and access the console in the center to raise the elevator to Liara’s level. You need to talk to Liara to disable the console. You can ask again about Benezia, if you didn’t before. Then there will be a tremor in the mine, Liara will say that the ruins are not entirely stable and that the mining laser must have triggered a seismic event. You will tell Joker to get the Normandy over to the ruins as quickly as he can make it. There is an auto-save here if you have it turned on, then the elevator will rise to the highest level.

Getting Out[edit | edit source]

Just when you think you are free, you arrive at the top level to a stand-off with a krogan and some geth. You can answer him any way you like but no matter your choices it will always lead to a fight. There are two Geth Shock Troopers, a Geth Rocket Trooper, a Geth Sniper, and a Krogan Battlemaster to deal with. If the mission is done early, this fight can be extremely difficult.

The pillar to the southwest can provide cover from most of the geth and the Battlemaster. Warning: Each pillar will occasionally release a cloud of steam which will damage characters huddled against it, however. Interposing the pillar between Shepard and the enemies without getting "formally into cover" is one way to mitigate this effect.

First take out the Shock Trooper on the other side of the room. Then, quickly turn around as the second Shock Trooper will approach behind you. Be wary, the geth can flank your team easily in this circular room. The Sniper will normally remain put where it spawns.

Insanity Tips: The geth won’t target Shepard with anything deadly in the first couple seconds, so take the opportunity while the geth are all standing exposed and out of cover to whip off some can't-miss abilities like AI Hacking, Overload, Lift, and perhaps one quick volley before running for cover. Rocket Troopers have that peculiar combination of deadly attack and weak defense that makes them great to take out (and/or hack) early. Also consider putting something tough and nasty like a Shock Trooper into Stasis if you have it to keep the early numbers down. Don’t worry about the Battlemaster yet because he won’t start aggressively closing range and charging until most or all of the Geth are down. Once a couple of geth are down, make an effort to flush the sniper out of his hiding place before the Battlemaster starts charging, as fleeing from the Battlemaster while under sniper fire gets pretty dicey. The sniper can be dealt with via grenades, by sending the squad over, or even by running over and (carefully) doing it yourself – fortunately snipers don’t live long once you have a clear shot at them.

Once all geth are taken out, or the sniper is the only one left, the Battlemaster will usually charge right at you. Be alert for this moment as he can take out the whole squad within a matter of seconds. Biotics and/or Neural Shock can be utilized to disable him. Lift is probably the most dramatic ability in this combat, because if deployed when the krogan is charging he will go flying across the room away from you with all his momentum, and if deployed when he is almost dead will allow you to prevent him from regenerating. In any event, take every opportunity to knock him off his feet, and then fill him with holes while he’s trying to get up. If the squad has insufficient crowd control capabilities, then keep on the move, and run and gun.


Be careful because like all krogan if he is not killed in the air, the Battlemaster gets a second life once he is killed. Try to either kill him in the air, or blast him as soon as he falls.

Once the last enemy falls, a cutscene will play showing the squad and Liara waiting at the barriers. Another shake drops them and they start running. The ruins are collapsing around the squad as they make for the exit. They only stop once they are out of the ruins, and the Normandy is hovering above them.

Normandy[edit | edit source]

“Too close Commander, 10 more seconds and we would have been swimming in molten sulfur. The Normandy isn’t equipped to land in exploding volcanoes. They tend to fry our sensors and melt our hull. Just for future reference.”

Joker welcomes Shepard and the squad back to the Normandy with more than a bit of sarcasm. If Shepard already finished Feros this conversation will be interesting. After a few questions Liara offers to link her mind with Shepard’s to try to make sense of the vision from Eden Prime. The joining doesn’t produce any results and Liara gets tired. Dismiss the crew and you can choose to talk to the Citadel Council. If you do, you can choose to respond to their questions in whatever way. Once you are done with the Council, then continue with the game.

Alternative scenario[edit | edit source]

If this mission is left until last (after even Virmire), Liara's reactions are very different. Down in the Prothean ruin, she refuses to believe Shepard and the team aren't a hallucination until they actually release her from the energy bubble, claiming that she's just conjuring up a protective figure like a Spectre to stop herself from going mad. She cringes in fear from the krogan battlemaster, begging Shepard not to let him take her.

During the debrief, as she hears about the evidence of the Reapers, the Cipher from Feros and Shepard's visions from the Prothean Beacons, Liara gets angry that all her decades of research have been wasted - in a short period of time the squad have stripped all her discoveries away. She begins to calm down when she realizes that her expertise is the only way for Shepard to interpret the vision, and joins the squad to help in the upcoming battles.

If you complete the assignments on Feros and Noveria prior to rescuing Dr T'Soni, you will still receive the hallucination dialogue, however she will not react fearfully to the Krogan Battlemaster.

Enemies[edit | edit source]

Trivia[edit | edit source]

  • When on Therum's surface, suffering from the planet's incredibly hot climate, Kaidan jokes "At least it's a dry heat." This is a reference to Aliens, where Hudson says the same thing about the alien nest under the atmosphere processor.
  • While Shepard is escaping from the collapsing facility with Liara, a krogan blocks the exit, forcing a fight. Shepard states the obvious, that this place is falling apart, to which the krogan will say "Exhilarating, isn't it?" This is a possible reference to Star Trek III: The Search for Spock, in which the Klingon Kruge utters the same line when confronted by Captain Kirk on the rapidly decaying Genesis planet.
  • On the PC version of Mass Effect, large areas of land on the planet's surface may not render properly causing swaths of landscape to be a black hole, although the topography and ability to traverse these areas is retained. This error can be fixed by using repair feature of the configuration utility and deleting local shader cache files.

References[edit | edit source]

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