Broken Plains Wilderness is a location in Tyranny.
The Bronze Brotherhood sent a portion of their forces to hold the Broken Plains, hoping that their presence in this uninhabited wilderness would allow them to respond to threats on both ends of Haven's borders. The Disfavored have aggressively attacked the rebels here. With only a handful of small encampments and few fortified positions, the Brotherhood's control of this area remains tenuous.
Points of interest
Right next to your entry point is a wounded bruiser. Talk to him to learn that the Disfavored are waging a campaign of extermination against them. You can use Athletics 42 or Subterfuge 42 to score some new recruits for the Chorus.
Sweep through the area to find the squads. They're spread out in two-man groups, roughly forming an X. The groups to the south-west and north-west are larger. The south one has a total of six troops, including the Lieutenant and two mages, the north one two Runners, two Stone Shields, and an Earthshaker.