Hunting the Hunter

Hunting the Hunter is a side quest in the Fallout 4 add-on Far Harbor. This quest is unavailable until the player character has recovered the Courser chip during Hunter/Hunted and completed the sidequest The Arrival for Chase.

Walkthrough
Once the Sole Survivor has been welcomed to Acadia and helped out Chase, talking to Dejen on the first sublevel will bring up the topic of an Institute Courser presence on the Island. Dejen claims the courser tracked Chase all the way from the Commonwealth because she "screwed up" during her last visit there and tasks the Survivor with hunting down and eliminating the threat to Acadia. The target can be found at a fixed location, near a roadside shack west of the MS Azalea and southeast of Acadia. Once the courser has been eliminated, returning to Dejen ends the quest and the Sole Survivor gets a discount of 20% when buying or selling from now on.

Bugs

 * After killing the Institute Courser, the Sole Survivor could be unable to speak to other NPCs, starting line being constantly "Hey, Dejen". To fix this, just end the quest by speaking to Dejen again.
 * The mission may not ever start, as Dejen will not initiate the quest dialogue. This is caused by a script at the end of The Arrival (the one that has Chase give out a reward), which will only start the quest if the player character is not currently allied to the Institute. Even if they are later Banished from the Institute, there is no second chance to start the quest.
 * To check if this issue applies, use the console command, which will show the quest as stopped if it applies. It can be fixed by using the command . This will start the quest dialogue.
 * Sometimes after arriving at courser's location you may find him fallen through the terrain. To fix that, enter tcl command to disable clipping, float to courser to target him (move closer and click on him, you'll see his RefID on top of the console area), float back slightly above surface and enter "moveto player" command. This will teleport the courser to player location, and thus, above the surface. Save the game, revert clipping mode to normal and reload the saved game.