Hi,

I'm writing to you about the orc quest (I didn't remember the name...). I have to talk to Atub to do this quest, but she started to attack me when the giant attack the orcs. I kill Atub (I didn't know it was a mission) and now, I can't do this great quest.

Why they just don't put the quest to the chief of the clan and we can reconciliate with them?

Thx Bethesda to read that and make this change, because it's very annoying.

Reload from an earlier save if you have one available. If not, then you're stuck.

Without giving away plot specifics, the Chief is involved in the quest, but not in a good way, so giving the quest to the chief would not work here.