Which fictional artifact is central to the plot of Assassin's Creed II?

The Apple of Eden is the fictional artifact central to the plot of Assassin's Creed II.

In Assassin's Creed II, the Apple is a Piece of Eden sought by both the Assassins and the Templars. Its powers include influencing perception and controlling minds, making it one of the most important artifacts in the series' mythology.

Ezio Auditore encounters the artifact while pursuing the people responsible for the destruction of his family. The Apple becomes linked to the broader conflict between the Assassin Brotherhood and the Templar Order, as well as to the enigmatic First Civilization.

The series contains several other Pieces of Eden, including Swords, Staves, and Shrouds. Those names can make artifact questions confusing, but Assassin's Creed II specifically centers on an Apple. The game's historical story takes place mainly in Renaissance Italy.