The assassination of the Baron resulted in the retreat of the French forces from Rome. Along with this and the death of his Banker, Cesare's efforts for a "united Italia" were swiftly dematerializing. Infuriated, Cesare returned to Rome to confront his father and demand answers. Ezio and Lizzy used the key they obtained from Pietro to enter the Castel Sant'Angelo through a side entrance. Once inside, they made their way to the Pope's chambers.
“Lizzy if anything happens to me, run. Do not stay and fight.” Lizzy looked at her master in shock. “But why?” Ezio looked Lizzy in the eyes. “Elizabeth do not talk back. Cesare has the Apple of Eden. He wields power that we could never comprehend.” Lizzy nodded. She doesn't understand anything about the apple that Ezio has taken a liking to. “Here is the entrance to the Castel Sant'Angelo, I just hope they didn't start the party without us.” Lizzy used Pietro's key and opened the cellar door.
Ezio entered the premises of Castel undetected. As he advanced, he saw Cesare riding alone. Lizzy followed Ezio, making even less noise as she slid along the floor. “I want to see the Pope!” Cesare yelled at the guard. “His holiness waits for you at the top of the Castel, in his apartments.” The guard bowed at Cesare. “Get out of my way!” Cesare pushed the guard out of the way and stormed inside.
Cesare entered the castle. Ezio and Lizzy heard shouting coming from Lucrezia's room, so they went to investigate. They heard Lucrezia talking to a few guards.
“I don't understand. I ordered a fresh batch of la cantarella last night.”
“I am terribly sorry, mia Signora, but the Pope has taken it all.” The guard bowed. “Where is the Pope?” Lucrezia asked. “He meets with Cesare.” Cesare is here? Lucrezia wondered. “Strange. He did not tell me Cesare has returned.” Lucrezia left the guards. “Come Lizzy, lets eavesdrop on the Pope” They made their way to the pope's window. The two assassin's didn't have to work very hard on the eavesdroping, Cesare's voice stretched for miles.
“What has happened here?”Cesare grabbed his father's cloak. “I do not know what you mean?” The pope did his best to play dumb. “My funds. My troops. Gone!” Cesare started to shake his father violently. “Financial difficulties strike all of us, even those with an army.” Cesare let his father go.“You intend to give me money?” The pope looked Cesare sternly in the eyes. “No, I do not.” Cesare started to laugh. “Then I will use the Piece of Eden to get what I want. Your help is not necessary.”
Ezio looked inside. Cesare picked up an apple from the bowl on the table nearby and took a large bite from it. “That has been made abundantly clear to me. Are you aware that the Baron de Valois is dead?” Cesare choked on his apple. “No. Did you-” Te pope held up his hand. “What reason could I possibly have to kill him? Was he plotting against me with my "brilliant," traitorous, Captain General?” Cesare was outraged. “I do not have to stand for this.” Cesare made his way back towards his father. “The Assassins murdered him.” The pope said calmly. “Why did you not stop them?” Cesare grabbed the pope's cloak again. “As if I could. It was not my decision to attack Monteriggioni, it was yours! It is high time you took responsibility for your actions.” The pope slapped Cesare's hand away. “My accomplishments. Despite the constant interference of failures like you.” Cesare walked towards the door to leave. “You are not going anywhere. I have the Piece of Eden.” Cesare stopped dead in his tracks. “Get out of my way, old man.” The pope didn't budge. “I gave you everything and yet it's never enough!”
Lucrezia ran into the room and interrupted Cesare and Rodrigo.“Cesare! He intends to poison you!” Cesare tried to spit out the apple he had bitten into earlier. “You would not listen to reason.” Cesare glared at his father angrily. “Father. Do you not see? I control all of this. If I want to live, I live. If I want to take, I take. If I want you to die, you die!” Cesare forced the poisoned apple into Rodrigo's mouth and kills him.
Cesare then pointed at his sister. “Where is the Piece of Eden?” Cesare started to choke her. “Stop! I know where it is.” Lucrezia started to cry. “And you did not tell me he had taken it?” He held her neck tighter. “Cesare... It's me... your queen.” A tear fell from her eye. “You are my sister. Nothing more. Where is it?” Cesare's anger was abundant. “You... never loved me?” Cesare squeezed her harder. “Where is the Apple? Tell me.” Lucrezia spat in Cesare's face, to which he slapped her. “Tell me!” Eventually, she gave in and told him the location of the apple. “Smart decision, little sister.”
“Well I've seen enough, right Master?” Ezio was already inside. Cesare already left. Ezio approached Rodrigo and closed the poor man's eyes. “Requiescat in pace.”
“I know... I know where that bastard is going. San Pietro... The pavilion in the courtyard.” Ezio nodded. “Thank you.”
“Lizzy it is time for you to go.” Lizzy was shocked. “But master you know I can run faster than you, why are you telling me to not help?” Ezio slapped Lizzy on the face hard. “Do not talk back. I do not need you to get killed.” Lizzy stood there holding her cheek. Eventually she complied and slowly walked away. “Poor girl, I had to be rough. Even I do not know the power these things possess.”
Ezio left the Pope's quarters to find the artifact, and tried to exit the Castel through the front gates, though he ran into Cesare on his way out. “Assassino!” Cesare staggered onto his horse and rode away. Guards started to run towards Ezio. “Cazzo.” The sound of gunfire rang in the distance and a guard fell over dead.
“Hello again Master, looks like you could really use some help.” Lizzy jumped off of her ledge and landed next to Ezio. “I thought I told you to go home.” Lizzy laughed. “Since when do I follow orders? Besides, you are in trouble and I am here! Do not worry, if the apple troubles you that much I will leave after I save your ass from these guys.” Ezio smiled. “You are truly one of a kind. I am glad I met you Elizabeth.” He rubbed her on the head, and the two of them lunged towards the growing crowd of guards. Lizzy had no trouble dominating her opponents. Ezio destroyed the guards on his flank, and finally saw an opening. “Master you go on ahead and stop Cesare, I will hold them back!” Ezio jumped on his horse and rode off towards Cesare.
Cesare locked the gate behind him, preventing the Assassin from following. However, Ezio took a alternate route, by climbing to a ledge that led to the Castel's rooftop and jumping onto the ramparts to follow Cesare, before navigating through the Vaticano district. Ezio reached the golden monument first. “Eagle Vision.” The monument glowed. A small spot in it shined brighter than the rest, as indicated by his eagle vision. Ezio removed the gold plating and got the apple from within.