I need some Assassin's Creed help?

Okay, so I'm playing the first Assassin's Creed right now (I know, I'm super late) and I'm a bit stuck. I think I'm on Memory Block 4 if that matters, and I am in Damascus. I have completed all of the viewpoints and save citizen missions, and also gotten all of the vigilantes. However, I don't know what to do next. I've headed back to the bureau and I haven't been assigned anything else. What else is there to do?! Thank you for the help!!! :)