I caught the description for Ep1Ch5: The Core on this gameplay video. I didn’t bother tagging *spoilers* in the headline, because everybody should have seen this chapter a thousand time by now. If you haven’t you can catch the best videos I’ve found here.
Based on intel gathered by Fireteam Crimson, there is some concern re: Covenant ‘archeological teams’ operating in the area. Crimson’s being sent to investigate.
Interrupt the Covenant dig.