Some Mass Effect commanders are having difficulty uncovering exactly what happened to the missing survey team on Trebin in the Antaeus system inside the Hades Gamma Cluster.
This mission can be picked up in a variety of ways from a news video voice over while riding one of the elevators on the Citadel to uncovering a bit of information from a computer terminal while investigating Noveria. Either way, the quest will bring Shepard to the Hades Gamma Cluster, where they'll stumble upon the remnants of a camp and a sealed-off excavation site.
UNC: Missing Survey Team Quest Guide
Upon finding the excavation site, head up the ramp and into the ruins past the main door. A long tunnel will great the shore party—which they should waste no time getting to the end of. This is where they'll need to brace themselves.
Once they open the door to the main chamber, they'll be ambushed by a horde of human Husks. The Husks will dash toward the party in their typical mindless and aggressive fashion. It's Shepard's choice how they handle this, of course, but we recommend staying in the tunnel and essentially bottle-necking the main force before stepping inside to pick off the stragglers.
With the first chamber clear, one of the shore party members will likely make a comment about what happened to the researchers. However, this doesn't mean the quest is over. Shepard will need to find and unfortunately put down the rest of the infected researchers.
Head all the way to the back of the chamber where two doors are sealed shut—noted by their red door-control panels. Once the party gets close enough, however, the doors will burst open, revealing two smaller hordes of Husks that rush forward. These are the remaining researchers. Take them out as you see fit.
Players should receive a pop-up notification to signal that the last of the infected have been wiped out and the quest will complete.