to open to various times and locations throughout Earth's history, and brings forth legions of monsters to all of them. The Stranger, after obtaining the Quicksword that alone can harm her, locates the evil sorceress at Castle Shadowguard at the origin of time and defeats her. Ultima III: Exodus (1983) reveals that Mondain and Minax had an offspring, the eponymous Exodus, "neither human, nor machine", according to the later games (it is depicted as a computer at the conclusion of the game, and it appears to be a demonic, self-aware artificial intelligence). Some time after Minax's death, Exodus starts its own attack on Sosaria and the Stranger is summoned once again to destroy it. Exodus was the first installment of the series featuring a player party system, which was used in many later games. The Age of Enlightenment: Ultima IV–VI Ultima IV: Quest of the Avatar (1985) marked a turning point in the series from the traditional "hero vs. villain" plots, instead introducing a complex alignment system based upon the Eight Virtues derived from the combinations of the Three Principles of Love, Truth and Courage. Although Britannia now prospers under Lord British's rule, he fears for his subjects' spiritual well-being and summons the Stranger again to become a spiritual leader of Britannian people by example. Throughout the game, the Stranger's actions determine how close he comes to this ideal. Upon achieving enlightenment in every Virtue, he can reach the Codex of Ultimate Wisdom and becomes the "Avatar", the embodiment of Britannia's virtues. In Ultima V: Warriors of Destiny (1988), the Avatar returns to Britannia to find that after Lord British had been lost in the Underworld, Lord Blackthorn, who rules in his stead, was corrupted by the Shadowlords and enforces a radically twisted vision of the Virtues, deviating considerably from their original meaning. The Avatar and his companions proceed to rescue the true king, overthrow the tyrant, and restore the Virtues in their true form. Ultima VI: The False Prophet (1990) details the invasion of Britannia by Gargoyles, which the Avatar and his companions have to repel. Over the course of the game, it is revealed that the Gargoyles have valid reasons to loathe the Avatar. Exploring the themes of racism and xenophobia, the game tasks the Avatar with understanding and reconciling two seemingly opposing cultures. The Age of Armageddon: Ultima VII–IX Ultima VII: The Black Gate (1992) sees the