Ezio Auditore traveled to Monte Circeo, in order to destroy one of Leonardo da Vinci's most powerful machines: the Tank. In order to do so, Ezio had to infiltrate a heavily guarded factory, where these powerful machines were being made.
Arriving in the Borgia-occupied settlement, Ezio sought the engineer. Though he located the man in the outskirts of the fortress, he was protected by a bodyguard, preventing the Assassin from extracting any information from him. He thus merely tailed him from behind, listening to his target converse with his guard, regarding the machine's safety.
- Bodyguard: The invention is under guard and I caged the spies.
- Engineer: Those who attempted to steal from Cesare must be punished.
As the engineer entered the heavily guarded factory, Ezio quickly took an alternative route up the eastern walls, through a damaged section in the stones. Dropping down to where the engineer was standing, he confronted him.
- Engineer: What do you want?
- Ezio: Where are the plans for the weapon?
- Engineer: On a table, at the opposite end of the fortress.
- Ezio: And the device itself?
- Engineer: I am not sure. But you need three people to work it.
- Ezio: Come with me then.
- Engineer: No! We... we captured three soldiers, they are in a cell across from the plans. They will help you.
- Ezio: Bene (Good).
Ezio allowed the engineer to escape, and proceeded to make his way to the opposite end of the factory. Finding the plans at a small workshop, Ezio burned them using a torch, and made his way to the captured mercenaries. Dispatching the patrolling guard, Ezio asked the mercenaries where Leonardo's machine was hidden.
- Ezio: Where is da Vinci's machine?
- Mercenary: Follow us. They have hidden the path, but we discovered the entrance.
The Assassin freed and followed the men, however, they were ambushed twice by a large number of Borgia soldiers. Despite this, Ezio and the mercenaries eventually overpowered them and proceeded.
Once led to the entrance to a network of underground tunnels, one of the mercenaries commented on what Cesare intended with the tanks.
- Mercenary: Cesare will use it as the centerpiece of his army. He even plans a surprise assault at Sicilia (Sicily).
- Ezio: We will stop the attack.
Traveling through the deep passages, Ezio opened several gates for the mercenaries, and rebuked them for any unhelpful comments, until they reached the cavern where a working tank was stored.
- Mercenary: We need to open that gate.
- Ezio: I will find a way.
Ezio finds a way to the second lever.
- Mercenary: There you are! Finally.
- Ezio: Do not test me.
Ezio and the mercenaries discover a raised bridge.
- Ezio: I will lower the bridge.
- Ezio: Leonardo expects me to maneuver this? No instructions. Of course.
Ezio and his new allies took control of one of the working tanks, and staged a direct assault against the main weapons factory. Easily plowing through the countryside with the powerful weapon, they fired upon any mounted cannons, foot soldiers or other tank prototypes that blocked their path.
- Ezio: If ours can be injured, so can theirs.
- Mercenary: Just a few more shots!
Blowing the gates of the main factory open and entering the courtyard, they discovered several damaged siege towers, and cannons in the process of being repaired, as well as several working or half-built tanks.
- Mercenary: You are crippling Cesare's army!
After destroying the other war machines and siege weapons within the fortress walls, the mercenaries took their leave, and Ezio climbed up onto the walls of the factory.
- Ezio: I wish I could keep you.
Ezio nonetheless fired a mounted cannon at the tank, causing it to explode.
Ezio destroyed all the tanks, and their blueprints.
- Strangely, when Ezio had to beat up the engineer, the player could simply throw him towards the nearby hay bale, and the cutscene wherein Ezio interrogated him would still commence.
- While using the tank, Agile guards could be seen using guns, trying to shoot at the player. The tank would receive no damage and the guards would soon flee if the player opened fire on them.
- In order to achieve full synchronization, Ezio had to complete the tank battle without being damaged.
- Although the engineer mentioned three mercenaires, the third was injured and left in the cage. At the end, the mercenaries that accompanied Ezio seemed to leave in the opposite direction from where the Borgia fortress was - therefore leaving the injured mecenary behind. This might have been an oversight.