To unlock this quest, you must complete the quest "Proper Defenses". To start it, head to the south side of the island where Great Inagua is located and dock your ship in the designated area.
Fearing that Julien du Casse has spotted and recognized him in the Jackdaw, Edward decides to kill the Templar.
Hint:
Your objective will be to reach the north side of the island. Start by going ashore and climbing all the way to the top of the ruins in front of you. This will not be a difficult task, and the white markings will make it even easier for you to find the right path.
When you reach the top, follow the path deeper into the island. At a certain point, an enemy soldier will stand in your way. Kill him and keep going.
You can bypass the next few guards by jumping across the tree branches above their heads.
A little further on, you will run into guards interrogating a captured slave.
Wait until they disperse, then move along the branches above the one who walked off to the left and hang him.
Head up the path and kill the next soldier. This way, you - will - bypass the larger guard standing by the captured slave.
You can bypass the next soldier by navigating the next section - once again - moving across the tree branches.
Once you drop down to the ground, you will not encounter any more soldiers, so run forward until you reach a low opening that you will have to squeeze through.
At the waterfalls, turn right and continue forward, and after a short while, you should see Julien Du Casse's estate in the distance.
Hint:
Move forward. You will soon reach a clearing with a few soldiers. There is plenty of stalked grass, so taking them out quietly won't be a problem - but you can also take the path on the right and simply go around them.
On the next, slightly larger clearing with a few huts, there are several more soldiers. It is best to bypass them by moving across the trees and platforms above their heads.
On the other side of the clearing, drop down into a stack of palm leaves, then into the nearby bushes, and follow the path slightly uphill. You will have to cover a bit more distance, mostly by jumping across tree branches, before you eventually reach the estate.
Now you must make your way to the area on the other side of the mansion. You can do this whichever way you like. The easiest way seems to be going around the house on the right side. If you wish, you can also go through the building - entering it through a window, for example.
On the other side of the building, you will find a group of a few slaves guarded by three soldiers who are patrolling the area.
Hint:
Wait for the right moment, assassinate the soldiers one by one, then free the slaves and talk to them.
Hint:
The quickest and safest way to get near the docks is by using the stone stairs located near where the slaves were.
This will bring you to a viewpoint overlooking the entire docks and the ship. Julien is on board that ship.
Jump down into the water and swim toward the ship, preferably underwater so you won't be spotted. Climb up the side near the ship's deck, but do not step onto it - stay where you are hidden. Julien walks in circles around the deck, so simply wait patiently for him to pass by, then get behind his back and assassinate him with a single strike.
You don't need to worry about the other soldiers because Julien's death will trigger a cutscene, after which this quest will end and the next one will begin automatically - This Old Cove.
After completing this quest, you will obtain the first of the Templar keys.
