A Friend Indeed
You’ll receive this story mission from Dutch after saving the hostage not far from his bunker (or after you acquire 125 RP) and is best undertaken after taking out the second Cultist Shrine on the island.
A little northwest from the Silver Lake Boathouse, you’ll see a resistance member being assaulted on the pier by a cultist. Swim across the water (if approaching from Cultist Shrine #2) and then crouch before using your Binoculars to survey the area. You’ll see that there’s another cultist nearby, take aim with the crossbow and aim for a headshot (you can use [L3] while aiming to steady yourself). Quickly turn your attention to the second cultist near the resistance member and dispatch him before liberating him.
You’ll receive 50 RP for your troubles and then be given the opportunity to hire him, duly take him up on the offer and he will be added to your Roster.
Guns for Hire (and later, Fangs for Hire) is an incredibly useful tool in your quest to liberate Hope County. You can give them comands with the [left] Dpad button to order them to either attack the target via your Binoculars or to follow (by holding the button down) you. This particular man is a standard soldier but you’ll later come across Specialists who really add to the way you approach situations.
You should take Dutch up on his suggestion for your next course of action, the Forest Research Station located north of your position. Crouch as you get closer to your destination and then take out the Binoculars to survey the scene, the nearby fallen tree being an excellent position, where you should tag six cultists. The best course of action here is to sneak across to the north and try to aproach from the back of the station.
There should be a solitary cultist here, wait for him to turn his back and walk behind past the satelite dish and take him out. Head back around the way you came and another cultist should walk past the log piles here, take him out after he walks past you and quickly sneak over to the one a little further back.
Wait for the next one to patrol close to you and perform a takedown quickly before finally taking out the last two close together. If at any point you’re discovered, switch to a more lethal approach and gun them down with the aid of your new soldier friend, the mission concludes after rewarding you 600 RP.