Assassin's Creed 2 Walkthrough

Knock on Bartolomeo's door again for the last mission in the memory sequence. The first step is to climb the tallest tower in the area so that Ezio can set off a firework. Thankfully, the tallest tower is marked on the map for you. The west side of the tower provides the best climbing surface, letting you easily ascend to the top. Reach the very tip of the cross and you'll trigger a fresh cut scene.

You need to quickly get back down to street level to help Bartolomeo, who's not doing a great job of defending himself against Dante. Perform a leap of faith in the northeast direction and then quickly make your way to the new map marker. When you find Bartolomeo and his crew in a fight, try to spot out Dante (he's got a long robe and an axe) and focus your fighting on him. His axe is heavy and powerful, so you'll need to use disarms and sidesteps to defeat him. Damage Dante enough and another cut scene will interrupt the action.

Now Dante starts running away from the melee, leading you to Silvio Barbarigo. Run after him, and fast. Lock on for easy tracking and Dante will lead you through a line of enemy soldiers before he stops right next to Silvio. Break through the line of soldiers and you can perform a double assassination on the two targets. Mission complete.