This mission will only unlock after you have completed the previous one, Investigate Missing Scouts. You will receive word of Cerberus attacking and abducting civilians from the planet Benning from Traynor. Go to the Arcturus Stream, and then head to the Euler System before landing on Benning. When you exit your ship, you will receive word that Cerberus has engaged the civilian population nearby and is either killing or stealing them away. You will have to rush over to the battlefield to provide them with cover. Along the way, don’t forget to grab the Dog Tag next to a pillar in the outside area of the streets. This will help you solve a side quest on the Citadel, so although the item is small, be sure not to leave the streets without it.
As you proceed, watch out for Cerberus turrets. They will have set them up around the streets to aid in their invasion of Benning. You will soon stumble upon a small group of Cerberus soldiers. Kill them and move onwards. You will receive word over the radio that there are civilians pinned down ahead. Proceed to the battle. Watch out for civilians entering your line of fire. Take out the entrenched Cerberus troops and speak with the civilians.
Another wave of Cerberus soldiers will run in as you converse. Head into the building to the side to get a position above your enemies. Order your squad to remain on the ground to protect the civilians from frontal attacks. Look down upon the enemies and kill them with a scoped weapon. Alternately, if you don’t have a Sniper Rifle or something of the sort, send someone like Garrus up into the building while you manage the defensive efforts on the ground. From here, the civilians will proceed down the path towards a safe zone. You will have to protect them from snipers first, so look above to find the enemies. Then, when the snipers are done with, more enemies will flow down from the ladder next to the civilians. Grab the Capacitor Helmet as you proceed down the walkway.
After holding the landing pad for several waves, Cortez will return with the dropship. Load the civilians into it and leave to complete the mission.