Could anybody tell me what are the victory objectives in Bratt mission 6, The Offer?

I'm playing mission 5, killing the units in canyons. Obviously not all units in the canyons need to be killed, but the problem is that once I killed them, mission 6 was loaded up and immediately completed, throwing me straight into mission 7 with all my army getting lost in the process.

So, I need advice on what NOT to do in 5 to avoid autocompletion of 6. Alternatively, a working save from missions 6 or 7 would be appreciated. (Or does the story fit my situation, should I be doing mission 7+ emptyhanded?

hmm, replaying level 5 less aggressively actually led to a solution that seems to have discovered a glitch. Objective of 6 is to destroy HQ on Tharn, which I most certainly haven't done in my play of 5....