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Assassins Creed: Brotherhood Walkthrough Sequence 1: part 1
Assassins Creed: Brotherhood Sequence 1: part 1
When the cutscene with Mario is over, enable eagle vision and climb up following the highlighted path. Then Follow Mario untill you reach the gates.
Once the gates opened you will be attacked. You must kill all the enemies before you can continue. Keep following Mario across the rooftops until you reach the tower. After the cutscene the game wil really start.