Oasis of Ahil-Tar Side Quests

Evacuation:

After accepting your reward the Commander will once again be available to give you your last quest from him:

The moment you click OK a portal will pop up below you and a bunch of undead and trolls will appear lead by a unique Fire Troll:

The settlers will go through the portal but they won't get hurt by the monsters so don't worry about them. The monsters are spread all through the town and sometimes outside of the fence, so you must do some searching to get them all. You'll know once you have since a "group eliminated" message will appear. Once they are all dead go speak with the Commander for your final reward:

If you encounter the common glitch where you have killed all the monsters and the Captain won't speak to you than you can go to the well in the center of Bellevue (the one next to your stash) and find the settlers there:

Speak to any of them and they will reward you: