If you're an archer, you'll need to do the A Matter of Perspective quest. If you're using a game controller with your PC, you may find (like I did) that each of the targets you're to destroy shows up as "Invalid target"--you can't shoot at them! Makes it impossible to complete the quest.
It seems this is a bug with using the game controller. If you switch to the keyboard controls, you can target and shoot. You can still move around using the game controller, and of course you can switch back once you complete the quest.