This quest is not available in game.
Travel to Plaguewood, northwest of Light's Hope. Destroy 8 Scourge Structures by using Smokey's Special Compound at the Mark of Detonation planted inside each building. Smokey has had the Ziggurats and Slaughterhouses marked.
Once you plant the bomb, leave the building and marvel at your handiwork.
By the way, Smokey's Special Compound is rather... unstable.
While you were gathering the supplies, I had some of my people handle marking the Scourge buildings we need demolished.
Here's the plan: I'm going to give you ten sticks of my special compound. You're going to take them over to Plaguewood and plant them inside the Scourge structures that I've had marked for detonation.
<Smokey snaps his fingers.>
Bing! It's just that easy.