Specialist: Grace
Head to the location called Scrapfarm to find Grace. The location is occupied by highwaymen so deal with them as necessary. Talk to Grace to start this mission.
Grace will give you the location where her prototype weapon has been taken. The old train yard is of course occupied by highwaymen. Grace’s weapon is stored inside a locked train car. Get rid of the guard and open the train car.
Pick up the saw launcher inside as well as some ammo. Head out and kill the remaining enemies in the train yard. You can even free a bear from its cage to cause havoc. Just make sure you’re in higher ground to avoid getting pummeled by the bear yourself.
Kill the bear or let it escape then you’ll have to find and retrieve three stolen supplies. The supplies are not marked by default so you’ll have to find them yourself. The first one is inside a closed train car with a switch. Be careful because there are several skunks inside. As soon as you open it, get it out of the way then kill the skunks. Once clear, head inside to loot the supplies.
Another location of the stolen supplies are located in the elevated container as shown below. Climb up the nearest ledge then jump to reach it.
The last location is a bit tricky to reach. First, climb the nearby water tower then use the zipline. You need to jump right as you get near the pink-painted container since staying in the zipline will just automatically transfer you to the connecting zipline that leads back to the ground. If you do this successfully, you’ll be able to land exactly on that container’s ledge. From there, go around and climb the roof to reach the supplies behind the bars.
After collecting the items, get out of the container and meet up with Grace who’s nearby. Talk to her to complete the mission.