I've been playing through Assassin's Creed 2 and am on Sequence 13 where you must kill the 9 lieutenants. I've killed 8 of them and suddenly the final objective marker for the 9th has disappeared. It was there before I killed the 8th. I've climbed every tower, so there isn't any area I haven't explored. Is there something I'm doing wrong?
Alternatively, is there a way to recover one of the past save files so I don't have to start from scratch?
Any help you can provide is greatly appreciated!