The Dust Men have kidnapped Zeke and are holding him in the middle of their fortress on the pier in the southwest section of the Warren. Inside the fortress, all the shipping containers will be opened up and you have to work your way through a maze with Dust Men around every corner.
Into the fortress[edit]
After your first couple of encounters, you'll see steam jetting out from the wall in front of you. Step in front of the red pipes and press 
to turn the valve and move the steam jets higher so you can get under them. Run down to the other valve and note the ladder to your left. Turn the second valve, then run and climb the ladder as fast as you can before the steam starts jetting out again.
From the ladder, jump to the wire and cross over the steam. Around the next corner is a bomber; deflect the grenades with Shockwave and shoot the guy off the bridge. Past him, as you twist around through the maze, you'll have to take out a machine gun turret. Dodge behind the shipping container and use it for cover while you Precision head shock the gunner.
Above the gunner is a bomber, but you may not be able to reach him until you pass through the small tunnel. Just watch out for his grenades and dodge them or Shockwave them away. As you walk down the long passage, a fence drops in front of you. Climb the ladder to your left, throw a couple Grenades to soften up the Dust Men and glide over the fence.
Work your way down, but watch going around the next corner. At the top of the ramp is a gun turret and the Dust Men will roll exploding barrels down on you. Try to shoot the barrels as they're released so they blow up in the Dust Men's faces, and lob grenades at them to keep them busy.
Find Zeke[edit]
At the top of the ramp you'll have to climb the containers to get through to the next section of maze. Take out the Dust Men below before jumping down and dealing with more mobs on top of a wall. When the wall is clear, climb it and take out the bomber on the other side.
Around the corner is a gun turret protected by chain link fencing. Make sure you're at full health, roll to the ladder and climb as quickly as you can, then glide to the top of the crates. Drop down behind the gunner, take him out, disable the gun and climb the wall to your left. At the top of the wall, climb the container to your left. This gives you a better field of fire to take out the RPG on the far platforms and the machine gun turret below.
When all the Dust Men are down, climb up to the platforms and run around the top of the containers. Keep moving, even though you come under fire. There are concrete walls in front of you and you can take cover behind them and snipe the Dust Men.
When the way is clear, glide down to the lower walkways and carefully go around, taking out Dust Men as you go. Most of the Dust Men are regular riflemen, but there will be a bomber or two in the mix. When you reach the crane, climb to the top and take out the mobs. Step in front of the control panel and press to lower Zeke to the street. Jump down and walk to the cage to free Zeke and end the mission.