Thrall: We have been unable to execute a vast majority of our battleplans. We are definitely being watched.
The Iron Horde must have scouts planted throughout the Blasted Lands. Victory is slipping away from us.
Kill 5 Iron Horde scouts.
Thrall: You killed how many scouts? No wonder we have been unable to execute our plans…
With those scouts dead we have a greater chance of catching the Iron Horde by surprise. Aka’Magosh, (name).
Subversive Scouts – Tips
You may find the Iron Horde Scouts around Thrall at the Shattered Landing in Blasted Lands. Two are behind Thrall. They are stealthed, but you can see them (transparent) atop the edge of the cliff. The Iron Horde Scouts teleport behind you once you engage them in combat. Just turn around 180 degrees (behind you).
Visit the Warlords of Draenor Quest Guides
Video found here.
Iron Horde Invasion Storyline