How Do you complete Memory Block 3?

After defeating Talal, I'm wandering around this level for quite a while without any clue in how I can complete Jerusalem.

What should I do?

After assassinating Talal, going back to the bureau and speaking with the bureau leader, if you are done with Acre, go back to Masyaf to speak to Mualim.

here is video. you can see what to do:

Here's how to complete all memories, from supercheats.com:

Acre Investigations

Memory Strand 3 - Pickpocket South: Scale the View Point northwest of the Assassin’s Bureau to mark the location of this investigation on your map. There are two men conversing in a narrow tunnel. You’ll have to get past a couple of guards if you take the direct route. Stand near the tunnel south of their location. Blend while the letter carrier approaches. Turn around and pickpocket him when he walks past you. You learn of a possible connection between Garnier and your target in Jerusalem, Talal.