Optional Objectives:
- Double assassinate Cockram and Bugress
- Free 2 pirates
Head to the marked location in the map to start the mission. After reaching the seas near Principe, you have to make your way to the southeast, where you have to sink five enemy ships. After clearing your path, head to the shore and dock your ship there.
This small settlement has several chests and animus fragments so it won't hurt collecting them first before moving forth. Head to the south and climb the tree trunk along the way to hop across the branches, get an animus fragment along the way and jump over the barricade.
After landing, you'll meet with Roberts. When the cutscene is finished, you'll have two new optional objectives available. Loot the chest nearby then follow the main path.
You can enter the encampment through the main gate or over its walls using the trees to the south. There's also a chest inside a small cave past the three guards.
Or you can also go through the ledges north of the main entrance and reach the cliff where the encampment's cannons are located. I suggest taking that route since it will be easier for you to route the enemies and patrols.
After taking out the guards, loot the chest between two huts further to the east. Move in to the location of the first pair of pirates about to be executed. You have to kill the gunners and guards quietly. Use your darts for maximum effect. It will be best to use a berserk dart on the officer since he can one-hit-kill anyone he strikes. (If an officer under the influence of a berserk dart hits you, you'll be critically injured). There's also a gunner on the nearby rooftop so taking out the officer and the gunner will make it easier for you to route the other guards in the nearby foliage.
After freeing up the first group of prisoners, you can do a Leap of Faith in the nearby branch to get the animus fragment or just do that later. The other animus fragment to the middle-north is also hanging at the edge of the cliff. You have to do a Leap of Faith to get it as well.
Head to the next set of prisoners and carefully take out the guards along the way. If you can also make your way to the guard tower/viewpoint to the southeast, take out the gunner and synchronize in it, it will make your job easier. Once the guards are clear, just sneak behind the two gunners and kill them to free the prisoners.
Once done, kill the officer standing in the main path, south of the second viewpoint, then climb the tower to the south again to find a chest.
From hereon, it's up to you what order you would like to take to get the remaining collectibles. When you're ready to complete the mission, head to the green circle and use your eagle vision to find your targets. If you're after the second optional mission, you'll only get a small window of oppportunity for the two targets to get close enough for you to score a double-assassination. You can always replay the memory to get all the remaining collectibles at this point OR collect all collectibles then reload your checkpoint.
The key point here is the stalking area nearest to the alarm bell. Take out the lone guard facing it then move to that specific stalking point. Wait for your targets to appear and walk by. When they're near each other, run from your cover and kill them both at the same time.
Video: S9-02-11.mp4
In the next phase, listen for Roberts to finish his speech and the mission will be complete after the very brief cutscene.