We must kill Blood Prince Dreven and his followers. I know of the place where they intend to go. Here is the plan.
You and Keeshan will make your way to the tunnels and act as bait, lure Dreven into a false sense of security.
Myself and the sentinels will seal the entrance to trap him and his allies shortly thereafter.
Then we kill them all. I'll send word to the others to get moving.