I can't figure out how to get to the balista. If I go to the gates I get shot with an arrow. The king won't speak to me. The obvious way lies through the guards who are battling, but that area is blocked off. I have nowhere to go and no one to talk to. What do I do?

Edit: Nevermind.. I got it. You have to go toward the tower where you're being shot from, but not toward the path that leads along the wall. It's a death trap. You are supposed to come toward the inner wall, then press the left mouse button to "drop" from the wall. :/

Check the inside walls - there are wooden structures there that allow you to climb down (leftclick)