A particularly tricky mission, the Colonist Transport Escort is activated by heading to the Colonist Transport during Chapter 3. Yes, this is during the battle with Eos. Note that this mission cannot be triggered if fewer than 20 civilians were saved during the Civilian Escort mission. The team must guard the truck as it slowly moves to the Containment Facility.
The transport will constantly come under attack from Immortals, Hulks, and most likely, large numbers of the Queen's Horde. The team will be split between clearing the front, covering the rear, and staying with the truck itself. Sonic Traps, Escape, and other stuns will be vital to complete this mission without casualties. This mission is incredibly difficult and considered by many to not be worth the 5 experience it rewards you.