Find Liara T'Soni

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. This is recommended to be your first core world mission as it will recruit your last squadmate.

Acquisition
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 Atriums Tau Cluster.

Walkthrough
You will be facing geth all the way, save for a krogan battlemaster at the end, so tech is helpful, Garrus, Tali, or Kaiden, based on your personal preferences, would help. However, Tali’s AI Hacking Ability, or Shepard’s, if Shepard is an engineer, is particularly useful in this mission.

Arrival On Therum
The Normandy swoops down and drops the Mako on the planet. Therum is a volcanically active world. While the Mako can take damage, it cannot survive contact with molten lava. If the Mako touches it then you will die. 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. Remember that every kill, not damage, outside the Mako gives more experience that a kill form inside the Mako.

The best way to get the max exp from killing Armatures is to shoot them from the Mako until they are almost dead, then exit the Mako and finish off the Armature. Keep an eye on the other Armature because a direct, or splash damage from a near hit can kill Shepard and your squadmates in one hit. Once both Armatures are down get back in the Mako and continue up the road, remember to not fall off the edge. This is a good save point. After you save the lava pit to the left wont kill you. It can be used as a short cut.

Industrial Outpost
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. First kill the turrets before moving around, keep moving or using the Mako’s jump jets to avoid the rapid rate of fire that the turrets have. Use the Mako’s main gun and machine gun to weaken the turrets, then exit, destroy, get back in, and repeat for all three turrets. Once all three turrets are down, backtrack a little and take a turn off to the left, or right depending on the Mako’s orientation. Once here you will find another turret. Repeat the same process and then save your game, the upcoming fight is hard and on higher difficulties, can kill you.

Inside the outpost are some Geth Destroyers, Geth Troopers, Geth Rocket Troopers, Geth Shock Troopers, and one Geth Juggernaut. There is 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 avoid cover. Whatever you do not use the Mako for cover because if it’s on fire it is possible that the Mako is destroyed and you reenter the Mako you will die. Once all the enemies are down reenter the Mako and drive it into the outpost. There are still two geth remaining, one at either gatehouse. The gates to the left, the entrance the geth is on the right. Move up slowly, send in your squad first to take it out.

Once it’s down grab the upgrade kit in the building, open the doors if you wish, then move across the camp. When you exit the building there are some industrial structures to the left, when you get to the last one, it has a wall that faces the interior of the outpost, there are two crates here, and you don’t have to decrypt them to access them. When you come out from behind the wall, there is a crate next to a tire that must be decrypted, access it. Get into the Mako and head to the exit wall. The geth here is on the left, follow the same routine, send in the squad first to lure it out, then full it full of holes. Once done, open the weapons locker, and open the gates allowing you to continue.

To The Ruins
Save your game before leaving. One you leave you will come under fire from another Armature further along the path. Follow the save tactics as above to earn max exp. During this fight there will be another Armature further along the path that will be firing the whole time. If you went far enough, two more will be 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. Once you are clear of the geth infantry focus you attention on the Colossus. The best way to take it out is to shoot it from the Mako until its health is a sliver, then exit the Mako and pound it with gunfire until it collapses. That is the best way to get the most exp from the encounter. 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. getting past them is easy as this next area is completely devoid of enemies. Just head to the next tunnel and enter it. There are two Rocket Troopers about half way down the tunnel, take the out with the cannon or on foot at your leisure. The other end of the tunnel holds 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. 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 but will give you less exp so make your choice.

Beyond The Rock Barrier
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, a Geth Sniper is in 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 and 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 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.

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 SAVE YOUR GAME.

Ruins 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 to a different location 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 once walking tank.

Once you regain control move immediately to the left and have your squad take cover against the crate the furthest left and forward. Put Shepard in the nearest crate to the left. 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, well it won’t be pretty. Just be careful when you lean out because an Armature’s pulse cannon is capable of taking you down in one hit. Also if it even hits near you then you can die. So move to the left when it is preparing to fire then back once the pulse passes. Keep your squadmates in cover because the second they move out they will be targeted by the Armature. However once the Armature’s shields are down then it is probably good because then you can take it down faster. Once the Armature falls head into the ruin.

Prothean Ruin
Once you enter the ruin head down the entrance tunnel when you can see the catwalk at the end of the tunnel send your squadmates first because you will encounter a few Geth Shock Troopers and Geth Snipers. There is 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 other elevator take cover because three Geth Assault Drones will come up from below. Once they are destroyed, overload, sabotage, AI Hacking, and good old fashioned gunfire work very well, head to the next elevator.

This elevator has a problem as it starts to short circuit as you go further down. Once the elevator screeches to a halt, exit the elevator and down the platforms. Behind this forcefield is someone, get near the forcefield to initiate a conversation with her. She will ask who you are and you can answer her questions as you like. 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 not you have to go hunting for a way past the barriers. She also says 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. 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 puzzle is different, requiring you to enter a five step code by the process of elimination. It can easily be cracked with the use of a pencil and a piece of paper.[[Image:LiaraStasis3.png|left|250px|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. Once you go down into the tunnel and then access the console in the center to raise the elevator to Liara’s level. Once you get up talk to Liara to disable the console. You can ask again about Benezia again, if you didn’t before. Then there will be a shaking, Liara will say that the ruins are not entirely stable and “the mining laser must have triggered a seismic event. You can tell Joker to get over to the ruins have something to say about that. There is an auto-save here if you have it turned on, then the elevator will rise to the highest level.

Getting Out
Just when you think you are home free when you arrive at the top level a krogan and some geth will pass through the flickering barriers. 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. Once you regain control head to the right and take out the shock trooper that heads this way. Once it is down stay out of sight of the battlemaster because he will take you down quickly. Take out the other geth first, especially the sniper. Once the geth are down focus on the battlemaster. Remember that krogan have regeneration, once the battlemaster falls he will get back up one time. To eliminate this, have him in the air when you kill him. This is why you leave him until last, focus on him and pump him full of everything you have to bring him down.

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 for the exit. The ruins are collapsing around the squad and once they are out then Shepard takes a few second for a breather with the Normandy hovering overhead.

Normandy
“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 Liara was rescued first then 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 choose to respond to their questions in whatever way you choose. Once you are done with the Council, then continue with the game.

Alternative scenario
If this mission is left until last, 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

 * Turret
 * Geth Armature
 * Geth Trooper
 * Geth Colossus
 * Geth Shock Trooper
 * Geth Rocket Trooper
 * Geth Sniper
 * Krogan Battlemaster