Assassin's Creed 4: Black Flag Walkthrough Part 75 – Sequence 12 “Ever a Splinter”

Optional Objectives:
Free 7 Guardian Hostages
Use the Observatory defenses to kill 4 guards

Once again, restock on your ammunition. Time to head for the Observatory once more. Head for Long Bay. You cannot fast travel to it directly but you can get close to it like Devil's Eye Cavern or any similar location. You will find 2 Man O Wars sitting in front of the entrance to the cove. The best thing to do is lure one out, capture it, then head through the opening to start mission.

Time to start freeing the Guardians who have been captured. This time they will be much more friendly toward Edward. Head onto the beach and up the slope to the marker to begin this part of the memory. Now just head in and toward the beach before the cave. When you get there start toward the Viewpoint. There are Guardians to free. On the far side of the tower you will see 3 Guards on some Guardian. Tag all the guards with Sleep Darts to bring this it a swift end. After that, free the guardians. Head into the cave next.

Once inside, go to the first Stalking Zone by the edge of the small cliff. Look down to find 2 of the 3 Guards on a pair of Guardians. Tag them both with Sleep Darts then drop down. Look West to find the last Guard and take him out as well. Free the Guardians after that. Now head back up the slope and move along the Southern side of the cave to the next group of Guardians. They are guarded by 4 Soldiers. Start in the back and tag them all with Sleep Darts. Knock them out to free the Guardians. After that you should be done with the first optional objective. Continue on in until you reach the first of the defenses. It looks like the defenses have been triggered.

Wait for the orange field to fade then head on through. Climb up onto the moving platform and deal with the 3 Soldiers on top of it. Look to the left. You need to jump onto the moving wall and climb up it to the right. Get on top of the platform there and then jump over to the right. Go across the ceiling beams and head for the marker that sits ahead. Grab the edge of the platform and it will swing in, dropping Edward down. Go forward after that. Time for a spot of fighting.

Torres has triggered the defenses around the central piece to what held the skull. You need to fight through his men to make it through to him. To complete the second optional objective, you need to throw them into the active force fields during the fight. Just focus on this option available through your counter attack until you complete it. When you do then finish off the rest with regular combat and head for Torres.

Use the platforms on the left to make it to the far side. After the ledge drops, go to the right. Swing across to the far side of the platform. There you will need to navigate through the force fields and make it up to Torres. Move carefully and watch where the fields emit between the stones. Shimmy past the first one on the right and stop. Head right then up after that to the top. Go right, pausing for the field then jumping the gap to go right and reach the top. On there use the moving platforms to climb farther upward. From there, make it onto the beam suspended by the roof the cave between the 2 moving platforms. Wait for the disintegration field to deactivate then strike down Torres and finish this memory. After that the Epilogue is very straight forward.

Congratulations on beating the main story of Assassin's Creed 4: Black Flag.