During this section you will need to stay close to the biotic in the party who is maintaining the blue energy shield against the Seeker swarms. Staying outside this barrier for too long will cause your health to drain rapidly so staying within the defined area of protection is a good idea. When you are ready to go, speak to your biotic and they will walk into the passage on the right. As you approach the end, a group of Collector Drones and Harbinger will hover in front of you, then land in a room down and to your left. Wait for the biotic specialist to take cover, then eliminate the enemies in the room below.
When the area is clear, speak to the biotic to move on. As you climb down the stairs, you will see a platform lower in the distance; from this a couple of Abominations and a Husk or two will run at you. Kill them and you will then be able to see several Drones accompanied by Harbinger fly into the right side of the area. Again you need to wait for the biotic to take cover and follow suit. From the cover you get, be sure to lean out and kill the enemies on the platform in front of you without leaving the protective barrier. When the area is clean, speak to the specialist to continue onwards.
The next place your biotic will stop is just ahead in a small chokepoint. Enemies will come at you from the front and will also climb up onto the small ledge to the left and drop down to attack you from here. You will be dealing with Husks and Abominations for the most part and a single Scion bringing up the rear of the attack. It is important to kill all the smaller enemies (especially Abominations) fast (so get friendly with your shotgun!) or the Scion will be upon you very quickly and with the limited area of protection, there is nowhere to run.
Speak with the shield-bearer when you are ready to move on again and escort the biotic through the hallway. As you do, watch out for a couple of Husks that climb up onto the platform from the left. When the group reaches the top of the ramp here, you will see the entrance you need to get to below. Unfortunately your biotic is starting to get exhausted and needs to get there quickly. The biotic will start jogging down the hill, so you need to catch up - you should be aware that Abominations and Husks will start popping up onto the ramp as you cruise down, so you will need to do your best to deal with them and keep them off the specialist. When you reach the end, you will see a scene.