Assassin's Creed Revelations Walkthrough  Part 9 – Advanced Tactics

Advanced Tactics
At the bottom of the tower one of Assassins runs up and informs Yusuf that two of the Assassin Dens are under siege. You must follow him and defend this hiding places.

Full Synchronization is achieved by performing a Zipline Assassination.

Follow Yusuf forward and stay on his heels.

To perform a Zipline assassination you will want to get on a zipline then, as you move along, hit your weapon button to bring about a quick death to your target. This is a simple memory to complete but the next one does more to introduce you to the game.