Arno Dorian is the French assassin who investigates a conspiracy in revolutionary Paris in Assassin's Creed Unity.
Arno is an Austrian-born Frenchman raised by the noble Assassin Grand Master François de la Serre after Arno's own father dies. When de la Serre is murdered, Arno is blamed for failing to protect him and is imprisoned in the Bastille. He later escapes during the French Revolution and joins the Assassin Brotherhood.
The main story follows Arno through Paris as he searches for the people behind de la Serre's death. His investigation overlaps with the life of Élise de la Serre, a Templar and Arno's childhood companion. Their relationship places personal loyalty alongside the traditional Assassin-Templar conflict.
Unity is set during the French Revolution and features landmarks such as Notre-Dame, the Tuileries Palace, and the Bastille. Élise is important, but she is not the game's main playable character; Arno is the central protagonist.