Dark Reign - Death Comes Swiftly

For this task you need to go to the Broodlands. Once you zone into the Broodlands (north out of Lavastorm Mountains) follow the blue line on your compass to your quest objective. (If you don't currently have your compass up hold ALT down and press D (Alt + D)).

This is one of the easiest tasks to do for The Dark Reign. All you need to do is pull the entire zone starting from the entrance following the blue line until it stops. Right here I kill all of the mobs and then run into the room marked with the orange bit of lines. Inside this room you'll find a few more spiders you need to kill for the quest.

After you kill these spiders in the other little room you'll see a blue dot. Here is where the last mob spawns for you to finish the task. That's all there is too it!