In this picture there is a screenshot of me in the location of the quest. The name of the quest itself is in the upper right corner of the screen.
http://imageshack.us/a/img827/7753/gw091c.jpg
The aim should be to defend two NPCs, but, even waiting quite a loooooong time, nothing happens: the NPCs don’t move and there is not a single mob coming.
Nothing at all.