Garry’s Mod is a sandbox mod for the Source Engine. Unlike normal games there aren't any predefined aims or goals. Players are given tools and are left to entertain themselves. The player is in a world where objects can be created and destroyed on demand. Where people can be created and destroyed with the click of a mouse. A world made for him. A world he made.
The team has split up, Garrus and Sukolenko's going for a stealth mission, as they both are trained in sneaking missions, the encounter with the Ceph had just shown how much the two untrained squad members were(Cp. Sykes and Tali) in stealth.
Going back, Lt. Adams asked why they'd come back, and if they accomplished their objective, they hadn't, but they were sure the new two-man team would.
They joined the main attack-team later, being put in Wrex's squad.