Mass Effect 3 Walkthrough
This is my favorite guide on the Citadel. Our Mass Effect 3 Walkthrough covers the entire spectrum of the single player story, multiplayer tips, and how to build a powerful army.
Horizon
This mission may change depending on if Miranda survived the events of ME2 and how you've treated her during your past meetings. You'll be fighting a mix of Cerberus and Reapers here, making it a good place to bring Ashley or James and Liara.

Upon reaching the front courtyard you'll be attacked by a phantom and nemesis. Order your team to distract the sniper first while you quickly gun down the run away ninja. Enter Sanctuary and check the area for extra medi gel and XP from the data pads. Destroy the basic Cerberus troopers and loot the area for a pistol scope.

Switch off the water pump and head across the newly accessible ladders. Grab the Rosenkov Materials shoulder guard and into the building. You'll be attacked by marauders, banshees, and ravagers. With these many enemies, quickly take them down with any grenades or keep them busy with a biotic blast.

Check the PDAs and collect research data. Clear out more Reapers (mostly Marauders) and equip yourself with both the M-12 locust and shotgun blade attachment. Climb up into the tower and take out the next wave of marauders. This time they will have plenty of barrier engines, so destroy the machines first.

Pick up the medi gel and head into the elevator. In the next room you'll have to deal with both brutes and a banshee. The room is big enough that you can circle around and kite the enemy while your teammates destroy them. Take more medi gel and the M-99 saber.

There will be one last computer to salvage before heading into the final lift. During the cut scene you will need a moderate to high amount of paragon or renegade to save Ms. Lawson. Otherwise, you'll be out another useful amount of war assets.




