Back in the Animus, you enter a final, damaged section of memories. If you play both Rogue and Unity, then watch this final act very carefully. You may notice a few interesting consequences that your actions in other games have had here in this scene.
Follow the Dignitary
Meet with your old dignitary friend and walk with him toward the palace. It’s a good way to avoid suspicion from the French guards, but you can’t go all the way in with him. Stop in the front yard of the palace and go forward alone. You spot your quarry entering the front door, but you don’t have a formal invitation. There has to be another way in.
Turn around and go to the left side of the building. Walk around the hedges and through the garden, and climb up the walls to a balcony above you. Get inside through an open door. Now you’re part of the party!
Locate Secret Meeting
Go through the next few rooms by blending with guests. Stay close to people at all times so that Shay doesn’t look like he’s doing anything dangerous here. He’s mixing! The guards stay out of your way if you do this, and if any block your route forward, just wait until they patrol elsewhere, giving you time to advance without being spotted.
Go back to the first floor by jumping out of an open window several rooms in. There’s a single guard below, but he can easily be dispatched. Proceed toward the back of the palace now that you’re on the first floor.
Again, stay with the party guests for cover. Cross the long room and look for your target as you reach the end. He’ll enter the room with one of his associates, but they soon split off. Follow your quarry for just a moment, and then put a blade in him to initiate Shay’s final scene.
You have now unlocked “No Page Unturned.”
Watch the last Abstergo scene as well, and then the credits roll.
“Templar Then, Templar Now” also unlocks when the credits finish. Congratulations! You’re returned to Shay’s memories and can collect items and upgrade everything in the game to your heart’s content.