Norwegian Outpost - North

Near the beginning of the level, you'll see some electrical fencing.  Do NOT attempt to cross it - the goal of this mission is to take the steps needed to turn the power off and make the fence safe to pass.

Head right from the electrical fencing and you'll come to a door.  Head into the building and down the hallway until you come to an electrical box.  Repair the box and the locked door that you passed in the hallway will now be open.

Go through the door and you will find Carter in the room beyond.  Carter will not trust you until you heal him, so you'll need to search the room for a health kit.  While looking for the medkit, you'll also find an extinguisher and some ammo.  Heal Carter with the health kit, and also give him so ammo to increase his trust of you.  You'll need his help with the electrical box that is also in the room.

Have Carter repair the electrical box, and while he is working shoot the two barrels blocking access to an adjoining room.  They'll explode and after you put out the flames with an extinguisher, you'll be able to enter the room and grab a blowtorch, some fuel, and some ammunition.

Now that the electrical box has been repaired, you'll be able to access the camera monitors.  Use the cameras to zoom in on the bulletin board in the next room and you'll see the access code for the locked door.

Use the code to open the locked door, and you'll launch a cutscene.  After it is over, give Cruz a weapon and some ammo, and then search the corpse in the room to find a key.  Also flip the power switch to turn off the electrical fence once it has been repaired.

Leave the room, but be ready for the things waiting out in the hallway.  Shoot the barrel in the hall to take some of them out.  Once you have eliminated the things, use the key to open the locked door in the hallway.  Take the items that you find in that room and then head outside. 

Once outside and head to your left.  Follow the light posts that you find and you will come to a corpse with a weapon and some ammo.  Return to the electrical fence and pass through to exit the level.