When you enter the Sector you call Troy on the radio - she gives you directions to reach her - and that unlocks the Achievement: Sightseeing (25g) Reach the Old Town.
You call the other Doc and he fills you in on the strategic difficulties - you explain that you need to find Jade and recover Zere's research - and he agrees to stay hunkered down.
As you loot your way along, head for the marker on the map - and note the military jets overhead. That is NOT a good omen.
Reaching the marker - which is the Tower for this area - unlocks it as a Safe Zone. Head up and look around to meet Michael - then go inside and talk to Troy.
You get a CS here - you get to talk to Jade and man is she angry at you! After that this mission is completed, you get your reward, and begin the next mission.