If you do the first invasion, then go get the naval mines before doing the west depot, you can't complete the camp defense quest. You go into the keep afterwards, turn on the turrets, go wake up the naga, and you just can't talk to marcus about it. You get 1 exp when you pay the ferryman.
If you do the west depot first, then go get the mines, it all works out. You get 1 exp when you pay the ferryman, and 2 more when you talk to marcus.
