Sequence 7 - Benvenuto
Speak with Leonardo.  Alvise will take you on a short Venice tour. Follow his footsteps  You will watch an unpleasant incident at the bazaar.
When you will be visiting the fortress you will learn some interesting things about how soldiers are dealing with citizens.  In the end you will find yourself near new Leonardo's office. 
Go to the place marked as a location of your next target (the villa that you have watched couple of minutes ago). You will see that some thieves are robbing a girl.  You must help her. 
Sequence 7 - That's Gonna Leave a Mark
First you have to deal with some soldiers.  Now, chase the woman (look out for patrol guards). 
At some point, she will stop - you must help her now.  Thieves will help you now - they will focus on guards. 
Pass guards that are standing near the bridge and get close to the river.  Woman will be in gondola - you need to protect her from archers. Climb up to them and kill some enemies. 
Soldiers are standing in visible places where you can get very easily. You do not have to finish all targets, many of them will not cause any problems. Last two enemies are located at the seaside.  In the end you will get to the thieves hideout. 
Take the girl out of the boat and bring her to the table located nearby.  A doctor will appear - you need to help him with minor surgery. In proper time, we attach gauze (CIRCLE). Now, speak with Antonio  then knock on his door.
Sequence 7 - Building Blocks
In a brief conversation Antonio will give you a strange brew and then he will instruct you to go to some of his people and look for the job.  You can start with a girl, who is standing next to the door. 
Sequence 7 - Monkey See, Monkey Do
You will learn a special climbing technique. First, Francesco will present it.  Then you have to try on your own (when you are hanging on the wall holding R1 press X and then CIRCLE to catch something above).