- 马里奥: "在所有人安全撤离之前，绝不能让博吉亚攻破城墙。Insieme per la vittoria!（我们要携手抗敌！）"
- 埃齐奥: "Insieme. （携手抗敌！）伯伯……要小心一点。"
- 马里奥: "我会的。"
- Machiavelli: "Once our enemies are dead we can speak of vaults and gods and ancient places. You should have killed him. We're sure to suffer for it!"
- Ezio: "I am not here to debate the past. Together, we should discuss the future."
- Machiavelli: "No. I am leaving immediately for Roma."
- —Machiavelli and Ezio's final confrontation in Monteriggioni.[来源]
Ezio arrived at the study with Caterina, where Claudia, his mother Maria, Mario, and Niccolò Machiavelli were waiting. Ezio told them of what he had seen in the Vault, and of his confrontation with Rodrigo Borgia.
He spoke of the "moving painting" of the goddess Minerva, who had told Ezio about a disaster that would occur in the distant future, as well as the existence of the Temples that could aid humanity. After her message, she had called out to a phantom named Desmond, much to Ezio's confusion. After this, the goddess had disappeared.
The others were astounded by Ezio's discoveries, and Claudia asked if the goddess had appeared human. Ezio told her that she had, though her words proved otherwise. Mario asked who Desmond was, and where the Temples that Minerva had mentioned were. Ezio could not provide the answer to either. Machiavelli then asked Ezio how it had ended with Rodrigo, if he had begged for mercy or had offered power in exchange for his life. Ezio told him that none of these had happened, confusing Machiavelli as he thought it odd for Rodrigo to remain so calm before dying, to which Ezio revealed he had actually allowed Rodrigo to live.
Enraged, Machiavelli lectured Ezio, saying that sparing him was a mistake and that they could only go searching for fabled Temples once their enemies were dead.
Ezio attempted to explain why he had spared Rodrigo, saying that they should forget the past and focus more on the future, but Machiavelli disagreed vehemently with him, and abruptly left for Rome.
As Machiavelli departed, Mario tried to comfort Ezio on his decision, stating that he trusted his judgement. After this, Ezio left the study and returned to his room. There, he undressed and bathed, and was soon joined by Caterina, who had come to comfort him. After the bath, Ezio and Caterina continued their "activities" in bed, which lasted until dawn.
- Mario: "It's the Borgia!"
- Ezio: "How did we not see this?"
- Mario: "They must have massed to the east during the night. We need to hold them off until the townspeople have escaped."
- —Mario trying to explain what's happening to Ezio.[来源]
As they finished, Caterina asked Ezio if he wanted to "go again," to which he replied that she need not ask. As they were about to begin, cannon fire could be heard from outside.
When Caterina wondered aloud what it was, Ezio assured her that it was just the mercenaries training with the new cannons. This was proven wrong, however, as a cannonball tore through the windows of Ezio's room, hitting the Armor of Altaïr and scattering it.
Surprised, Ezio got out of bed and hastily dressed himself. In a rush, he only had the time to take a common sword and his left Hidden Blade before heading out of the villa through the wall blown open by the cannonball.
Caterina left the room by the stairs, calling to Ezio that she would use her men to flank their enemies. After this, the two parted ways, with Ezio telling her to stay out of sight.
Ezio jumped onto the villa roof, where he was greeted by the sight of Monteriggioni heavily damaged by cannon fire, with its buildings ablaze and falling apart. As his eyes wandered, Ezio caught sight of a cannonball headed his way, which he only just managed to dodge.
Tumbling from the roof, he hit the ground, but was quickly helped up by his uncle, who informed Ezio that the Borgia were responsible for the attack. Ezio wondered how they had not seen the attack coming, to which Mario replied that they must have taken an alternative route to the east during the night.
As the villa sustained more damage, Mario instructed Ezio to climb the battlements of the city and assist the mercenaries while the villagers fled. Mario informed Ezio that he, in turn, would lead a frontal assault against the Borgia infantry.
Before their departure, Ezio asked if Mario had the Apple, to which he replied that he was keeping it safe. As the two parted, Ezio told Mario to be careful, and was reassured that he would.
Ezio quickly leapt from the balcony of the villa's courtyard and landed on a nearby horse, which he rode through the collapsing city. As he reached the side of the city walls, a nearby tower fell, killing his horse and throwing the Assassin from the saddle. Ezio grabbed onto a nearby scaffolding before he hit the ground, and proceeded up a ladder to the battlements.
There, he joined the mercenaries in manning the mounted cannons, using them to destroy the Borgia infantry, cannons and approaching siege towers. As Ezio and the mercenaries defended the city, the townspeople fled to the villa.
Just as the townspeople had reached safety, the Borgia were able to breach the city's defenses, with one siege tower successfully reaching the eastern walls. As a mercenary took his place as cannoneer, Ezio ran across the ramparts to aid the mercenaries being assaulted by the Borgia soldiers.
- “We've had too much bloodshed. I think a cleansing is in order. So, consider this as an invitation from my family... to yours.”
- ―Cesare, moments before killing Mario.[来源]
Ezio killed the commanding soldier from above and charged into the fray, disposing of the remaining attackers and swiftly killing two Brutes. As he did, the enemy forces finally breached the city gates, and Mario came through them, barely alive, falling to the ground right after being seen by Ezio.
Following close behind him was the Captain-General of the Pope's army, Cesare Borgia, accompanied by his sister, Lucrezia, his generals, Juan Borgia the Elder, Octavian de Valois, Micheletto Corella, a contingent of soldiers and Caterina trapped as a captive.
Cesare called out for Ezio's attention, stating that the Pope had told him about Ezio and his "little group of Assassins" and about the Apple of Eden, holding it up for Ezio to see.
Ezio rushed to Mario across the rooftops as Cesare quickly snatched the newly designed wheel-lock firearm fashioned by the Assassin's friend from Octavian, and pointed it to Mario's head.
Claiming that there had been too much bloodshed between the two families, Cesare fired the pistol and killed Mario, serving as an invitation from the Borgia to the Auditore to confront them at the center of their rule, Rome.
Subsequently, as Ezio watched his uncle's murder, he was shot through the left shoulder and lower abdomen by several of the arquebusiers positioned on the city walls, causing him to fall from the rooftops and lose consciousness.
- Claudia: "You're not coming with us? Where are you riding?"
- Ezio: "To Roma."
- ―Ezio and Claudia, before Ezio departs for Rome.[来源]
Waking up, Ezio was greeted by the sight of two mercenaries dragging him across the battlefield to safety. Ezio irritably demanded that they let him go, insisting that he could stand on his own.
As he did, the Borgia soldiers arrived to finish what they had started, and, knowing that he could not handle them alone, Ezio called for the mercenaries to aid him. Eventually, Ezio and the mercenaries fought their way through the city and reached the villa.
As he made his way through the city rubble, Ezio found Claudia and another group of mercenaries being assaulted by more soldiers. Ezio and his own group of mercenaries assisted them, and successfully fended them off. With haste, the group made their way to the Sanctuary, closely followed by Borgia guards.
One of the thieves of Monteriggioni, who had been about to shut the Sanctuary door, told Ezio that they had thought he had been killed. Before Ezio closed the passage, the thief left to aid the troops. After this, Ezio locked the secret door to the hidden passage, and descended the steps to meet up with Claudia, Maria and the townspeople.
In the tunnels below the Sanctuary, Ezio headed the escape through a long, perilous passage constructed behind his ancestor's statue, which led to the outside of the northern walls.
After a long journey, navigating through the complex structure and dealing with the guards that had managed to catch up with the group, Ezio and the other civilians managed to escape the city.
By then, the Borgia had assumed that Ezio was dead and had begun to recall their invading forces.
- Ezio: "Ah, Roma."
- Margherita: "Yes, or what is left of it since the Borgia came to power."
- ―Ezio upon waking up in Rome.[来源]
After the attack, the Assassins lost the Apple of Eden to Cesare and his armies. Escaping through the outer walls, Ezio demanded for a horse, and instructed Claudia to take their mother back to Florence. Claudia asked where he was going, to which he replied that he was going to Rome.
As the civilians fled Monteriggioni, Maria bid her son farewell, and demanded he destroy the Templars, but to remember for whom the Assassins fought. Ezio then immediately departed on horseback towards Rome.
Travelling along the countryside, Ezio steadily grew weaker from his injuries, before finally falling from his horse and passing out on the road. Some time later, Ezio woke up, dazed and covered in bandages. He was then greeted by the sight of a kindly woman, who had nursed him back to health and stitched his wounds.
She told him that a man had brought him to Rome and had left new equipment and Assassin robes for him. As Ezio dressed and prepared to leave, the woman instructed him to meet with Niccolò Machiavelli at the Mausoleo di Augusto.
Leaving the house, Ezio soon found out he was in Rome. With this, the Liberation of Rome and the insurrection of the Brotherhood had begun.