1 - The Artemis Tau Cluster

Your first lead involves finding the daughter of Matriarch Benezia, who is believed to be somewhere in the Artemis Tau Cluster. Access the Galaxy Map on the Normandy and select the appropriate cluster, then zoom in to view the known systems. Select the Knossos System to travel there. When you arrive, move your cursor to the planet Therum and select it to land on the planet.

2 - To the Refinery

The path before you is fairly linear. Take the Mako north and follow the path between the cliffs and the lava. Make your way around towards the south, at which point a geth dropship will deposit a pair of geth armatures in your path. Keep your distance and use your jump jets to avoid their attacks. There is a refinery to the east but the way is blocked by a large gate and three geth heavy turrets. Take the detour around to the north, which is guarded by only one heavy turret. This path leads to the heart of the refinery, which is guarded by regular geth troopers and shock troopers, but also by rocket troopers, which have weak personal defenses but a powerful ranged attack. Your toughest opponent is a geth juggernaut, which is a more powerful version of the destroyer you faced on Eden Prime. Stay in the Mako and keep your distance while avoiding enemy rockets. Search the refinery thoroughly, as there are a number of storage containers you can plunder. The controls to lower the north gate are located in the building to the northwest.

3 - Proceed in the Mako

Continue north, where you will encounter several more armatures. There are rocket troopers and a geth colossus guarding the entrance to the tunnel you must use to precede. Once again, keep your distance and zoom in with your turret to make dealing with these enemies easier. There are a small group of rocket troopers on the other side of the tunnel. Continue on until you reach another tunnel. You will encounter some rocket troopers inside the tunnel this time, along with more geth troopers and rocket troopers at the exit.

4 - On Foot to the Dig Site

You eventually reach a point where the path narrows and you must leave the Mako and continue on foot. Your radar will be jammed by a nearby sniper. Proceed east up the hill until you encounter geth troopers and rocket troopers. Stay in cover and pick your shots to avoid the missiles from the rocket troopers. There are also shock troopers and a geth sniper waiting in the clearing up ahead, so be on your guard.

5 - The Mining Camp

At the mining camp you are ambushed by a group of geth stalkers and a geth armature. Take cover, keep your distance, and take care of the stalkers first. Having squad members with tech abilities can help to deal with the regular geth enemies. There is also some cover on a small hill to the east that is perfect for taking down the armature from a distance. Spend as
little time out of cover as possible, and avoid the blast from its pulse cannon at all costs. Once all the geth are defeated you may proceed inside the mine itself.

6 - Exploring the Mine

Follow the ramps down into the mine. You will encounter some shock troopers and snipers along the way. Take the elevator down to the next level and follow the catwalks. As you approach the next elevator a group of geth assault drones will appear from below. Like the recon drones, they are resistant to biotics but susceptible to tech powers. Take the second elevator. At the bottom, climb down the debris pile and approach the asari behind the blue barrier.

7 - Freeing Dr. T'Soni

Liara T'Soni is trapped by a Prothean security device. Before you can get her out however, you must find some way past the barrier. Keep descending the ramps until you reach the bottom of the mine where you will find more shock troopers and snipers. At the far end there is a storage locker and a weapon locker. Return to the nearby mining laser and activate it using the correct sequence, A-X-B-Y (the code varies on the PC). This opens a hole you can proceed through. Activate the elevator at the end of the tunnel and take it up to Liara's location so you can free her.

8 - Escaping the Mine

It seems the mining laser has caused some seismic activity and you need to leave quickly. Take the elevator up to the top floor, where you will encounter the krogan Liara warned you about. You can't talk your way out of a fight, so you must defeat the krogan battlemaster along with his geth soldiers. The geth will try to move around the sides of the room to attack your squad from all directions. The krogan will also try to disable you with his biotics so he can charge and engage you from close range. Turn the tables and use your own biotics to make this fight much easier. When all the enemies are defeated it is a simple matter of racing to the surface to avoid certain death.

9 - Back on the Normandy

When you return to your ship the crew gathers for a debriefing. Liara will discuss her work as a scientist studying Prothean ruins, as well as your visions from the Prothean beacon. When the meeting is over you can choose whether to discuss the mission with the Citadel Council.

Mission Complete: "Find Liara T'Soni"

10 - Non-humans on the Ship (Optional)

If you speak with Navigator Pressly, he will express his concerns about having aliens on the Normandy. Talking to Ashley reveals that she has similar reservations. You can try to change their minds about non-humans, or chide them for questioning your authority.

+2 Paragon - "They're on our side."
+2 Renegade - "You doubt my decisions?"