Since the Beginning of Time the forces of Order and Chaos have been engaged in an eternal
stuggle to decide the fate of all Creation. That struggle has now come to the Mortal
Realm...And neither Man, Demon, nor Angel will be left unscathed....

Ultimately, as even Khanduras' good King Leoric fell under Diablo's wicked power, a lone
hero arose to challenge the darkness that had engulfed the land. After plumbing the hellish
depths of the labyrinth under Tristram, the nameless hero finally confronted the Lord of
Terror himself. Knowing full well that Diablo's spirit could never be truly destroyed, the
hero took the spirit of Diablo into himself, hoping that his own strength of will could contain
the demon within. The hero could never have known that his selfless act would not only
ensure Diablo's victory, but would irrevocably damn his soul for all time.

Diablo, Lord of Terror, and youngest of the Three Prime Evils, awoke from his long sleep
beneath the dark earth. Setting in motion a grand scheme to free his exiled brothers,
Mephisto and Baal, Diablo took control of the small western kingdom of Khanduras.
Working from deep within the ancient catacombs beneath the town of Tristram, Diablo
gripped the entire populace in a blanket of fear and paranoia.

As Diablo II opens, the hero, after containing Diablo's spirit, has journeyed to the East, and
has assumed Diablo's original appearance and power. He has gone to the East to raise an
army to aid him in his conquest of the world. Diablo's plans become revealed as the game
progresses; he desires to free his brothers, Baal (the Lord of Destruction) and Mephisto
(the Lord of Hatred), to reinstate the Prime Evils, the triumvirate of evil.