This Assignment can be accepted at any point after you gain access to the Galaxy Map for the first time. It takes place on an Uncharted Planet that you must explore with the Mako.
How to Begin
There are two ways to begin this Assignment, with the earliest being from the Citadel:
While on the Citadel, there is a chance to hear a news report about the missing survey team while riding the elevators. This will add the Assignment to your journal.
When on Noveria, you’ll find a Terminal at Rift Station that will have a report. This will begin the Assignment under the name Missing Colony.
Find Missing Researchers
Regardless of how you start this Assignment, make your way to the Antaeus system in the Hades Gamma Cluster, there you’ll find the planet Trebin. Once planetside, make your way northeast from your starting position to reach the Research Base as your squad points out that the place seems to be deserted. Leave the Mako and check the nearby buildings, you’ll find a computer in the northern one that points you to the nearby excavation site.
Explore the Excavation Site
Fortunately, the excavation site is nearby so return to the Mako and head north to locate and enter it. As you enter the main cavern here, you’ll be ambushed by a horde of Husks. Back up a little, using the tunnel entrance if need be and use Biotics such as Singularity to disable groups of Husks at a time. They may not be a danger from range but they can move quickly and at close range, can deal significant damage in a short amount of time.
Once the first group of Husks are defeated, consider saving your game and then press further into the main room, another group of Husks will ambush you. This is a good time to make use of the Plasma Cell Containments littered around the cavern. Once the final Husk falls, you’ll receive a message indicating that the last of the survey team has been defeated, completing the Assignment. Before you leave however, take the time to explore the two other tunnels here for the loot within.