Shadowkey:Dragonstar Gate Clear Hill
- Talk to Teresa Clothgen the Gatekeeper.
- Remove all the Skyrim Raiders near the city.
- Return and receive entrance to Dragonstar West.
Dragonstar is the largest city in the game, and the only one to have a locked gate. When you approach it Teresa Clothgen will talk to you from the other side of it, pointing out it is not safe to open the gate due to the Skyrim Raiding forces near the city. She says if you can get rid of them she will open the city to you.
Clearing the Hill
The Raiders she is referring to are on a hill very close to the city to the northwest, indeed it is possible you saw them and killed them on the way to the gate, as you have to actively go around them otherwise. Wiping out all the Raiders on the hill is enough to count for the quest.
Returning to the gate will result in congratulations and Teresa opening the gate.