.3J.02. Horizon: Repair Defense Tower

Head through the area, being mindful of enemies to the southeast. Watch out for charging Husks and Collectors in the confined space. Your first Scion encounter will be here; these slow, armored enemies fire shockwaves. Prioritize eliminating Husks due to their damaging melee attacks. On higher difficulties, Husks will have minimal Armor. The northern area is safe from additional enemies after the first wave. Collect the items, including an upgrade, and proceed through the door.

Upon entering the next area, you'll face a swarm of Husks from the north and east, along with Scions from the east. Deal with the Husks first, retreating south if necessary. If overwhelmed, sprint and use abilities or slowdown effects. Be aware that Scions' shockwaves can hit you even while moving if you are too close. Once the Husks are dealt with, focus on the Scions, using anti-Armor offense if possible. There is a Power Cell on the south side, but conserve ammo for the upcoming Praetorian. Hacking the computer initiates the next phase.

Collectors will fly in from the southeast, consisting of Drones, Guardians, and an Assassin, along with more Husks. Drones will continuously spawn and transform into Harbingers. After defeating six or seven Collectors, you'll get a brief respite to pick up ammo.

Thirty seconds later, more Husks will emerge from the northern units, and Collectors from the northwest. Use the transmitter for cover and proceed cautiously. Collectors rarely approach directly, allowing you to recover health behind cover.

Your position will automatically shift west. You will face the Praetorian, a flying enemy with a powerful laser-eye-beam-of-death attack and substantial Armor. Its laser beams originate from its middle, allowing you to shoot around the boxes while staying in cover. The Praetorian focuses on you and closes in quickly; maintain distance to avoid its heavy-damage melee attack and stun-inducing ground stomp. Use all Heavy weapons against it. If you run out of ammo, resort to hit-and-run tactics in a circle. The Praetorian pauses briefly between laser beams, providing an opportunity to shoot and sprint to new cover. On higher difficulties, it will deploy a barrier every 25% of its health.

Upon returning to the Normandy, the Illusive Man will provide an update and three new dossiers. You can now initiate loyalty missions for your current squadmates, specifically Miranda and Jacob. You can also Retrain Powers at the research terminal for 2,500 eezo. Since Miranda's and Jacob's loyalty skills are not particularly impactful, focus on recruiting for now. Each subsequent mission completed will unlock another loyalty mission.