Diablo II
Diablo II takes place after the end of the previous game, Diablo, in the world of Sanctuary. In Diablo, an unnamed warrior defeated Diablo and attempted to contain the Lord of Terror's essence within his own body. Since then, the hero has become corrupted by the demon's spirit, causing demons to enter the world around him and wreak havoc.
A band of adventurers who pass through the Rogue Encampment hear these stories of destruction and attempt to find out the cause of the evil, starting with this corrupted "Dark Wanderer." As the story develops, the truth behind this corruption is revealed: the soulstones were originally designed to capture the Prime Evils who were banished to the mortal realm after being overthrown by the Lesser Evils. With the corruption of Diablo's soulstone, the demon is able to control the Dark Wanderer. The soulstone of another demon, Baal, was united with the mage Tal-Rasha, who volunteered to absorb Baal's spirit in his own body and be imprisoned in a tomb.
As the story progresses, cut scenes show the Dark Wanderer's journey as a drifter named Marius follows him. The player realizes that the Dark Wanderer's mission is to reunite with the other prime evils, Baal and Mephisto. The story is divided up into four acts:
Act I - The adventurers rescue Cain, who is imprisoned in Tristram, and then begin following the Dark Wanderer. The Dark Wanderer has one of the lesser evils, Andariel, corrupt the Sisters of the Sightless Eye (Rogues) and take over their Monastery. The adventurers overcome Andariel and then follow the Wanderer east.
Act II - While the adventurers search the eastern desert for Tal-Rasha's tomb, the Dark Wanderer gets there first. Marius is tricked into removing Baal's soulstone from Tal-Rasha and the Archangel Tyrael charges Marius with taking the soulstone to Hell to destroy it. The Dark Wanderer and Baal join with Mephisto, open a portal to Hell, and the Dark Wanderer sheds his human form and becomes the demon Diablo.
Act III - The adventurers find the seat of the Zakarum religion at the Temple of Kurast, where the portal to Hell is located. They defeat Mephisto, who was left guarding the entrance, and take his soulstone.
Act IV - The adventurers slay Diablo in Hell and destroy the soulstones of Mephisto and Diablo on the Hellforge, preventing their return.
In the epilogue, Marius, speaking in a prison cell, indicates he was too weak to enter Hell, and that he fears the stone's effects on him. He gives the soulstone to his visitor. The visitor reveals himself to be Baal, the last surviving Prime Evil now in possession of his own soulstone. He then kills Marius and sets the prison cell on fire.
The story continues in the expansion Diablo II: Lord of Destruction where Baal attempts to corrupt the mythical Worldstone on Mount Arreat. Upon returning to the Pandemonium Fortress after defeating Diablo, Tyrael opens a portal to send the adventurers to Arreat.
good versus evil