The area where this mission takes place is an Infested zone but you won’t be able to burn all of the Nests while the mission is active. After reaching the mission marker, time will pass and you won’t be able to use your Motorcycle. The town is currently occupied by Rippers so you have to sneak or fight your way until you reach the survivor you’re trying to find.
To start off, go downstairs by the stream and examine the clue by the bank. Follow the tracks inside the restaurant. Once inside, Rippers will arrive. The town has a lot of cover and obstacles that you can use to flank these crazy cultists.
After taking out the first wave of Rippers, circle behind the gas station since there’s a sniper by the bar along the road. Sneak inside that building and get rid of the rippers inside.
Continue to the search area and you’ll encounter more Rippers. You don’t need to maintain full stealth so you can engage them in a gun fight if you want. Fight your way until you reach the blue-green house within the search zone.
Once clear, look for a ladder behind the house under porch. Pick up the ladder then climb up. Explore the second floor rooms until a cutscene is triggered. This mission is now complete and the next mission will start automatically.