Shadowkey:Dragonstar Gate Clear Hill

Fend off the Skyrim Raiders threatening Dragonstar. Quest Giver: Teresa Clothgen at Dragonfields Location(s): The Dragonfields Reward: 1500 Experience Points, Entrance to Dragonstar West

Dragonstar's Gate is closed to protect the town from raiders

Quick Walkthrough

1. Talk to Teresa Clothgen the Gatekeeper.
2. Remove all the Skyrim Raiders near the city.
3. Return and receive entrance to Dragonstar West.

Detailed Walkthrough

The Gateway

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:

(You hear a voice from behind the gate.) "I am Teresa Clothgen, gatekeeper for Dragonstar.
We cannot risk opening the gate until the raiders around the hill are eliminated.
If you do this, we can open our city to you. Otherwise, we wish you safe journey."

Consider them gone.

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.

Entry

Returning to the gate will result in congratulations and Teresa opening the gate:

"Clearly you are more than they bargained for. It is great fortune that Dragonstar found you at her gates.
I am indebted to you, as are the citizens of Dragonstar. Thank you."

It was my pleasure.

(You hear the locks grinding and chains being pulled.)