Stay awhile and listen... My name is Deckard Cain. I am the last of the Horadrim, a secret order that was assembled to protect humanity from the demonic forces of the Burning Hells.
Yet I grow old, and I must pass down my knowledge. Mankind must never forget our struggles against the Lords of Hell, for they will not rest until they hold sway over all.
The Prime Evils--Diablo, Baal, and Mephisto--once wreaked havoc on our world, before the Horadric order was formed to hunt them down and imprison their essences within enchanted soulstones.
Buried beneath the town of Tristram, Diablo's soulstone lay undisturbed for generations... until the fateful day he was released and our holy cathedral was transformed into a gateway to the Hells.
The Lord of Terror drove our good king Leoric to madness and possessed his youngest son, Albrecht. With Leoric's mind poisoned and Diablo's minions prowling the night, chaos and fear gripped Tristram.
Just when we had given in to despair... hope emerged. Leoric's eldest son, Aidan, returned from abroad and pledged to vanquish the demonic evil that had turned our lives into a unending nightmare.
He stormed into the labyrinth beneath Tristram's cathedral and vanquished the Lord of Terror himself. We all heard the demon's terrible death-cry echoing up from the cursed depths.
Tristram was saved, and at last we knew peace. But where our torment had ended, Aidan's had just begun. He seemed distant... troubled by some unseen burden. Then one day, he simply vanished.
Following his disappearance, a new wave of demons ravaged Tristram. With no one left to defend us, the town was reduced to ashes. My friends... were butchered and raised from the dead.
I alone was spared, caged and forced to witness Tristram's defilement. I thought I would die there in the ruins of my home, but I was rescued by a group of brave heroes.
They spoke of a great darkness stretching toward the east, and I knew in my heart it was Aidan. This once-valiant man, who became known as the Dark Wanderer, had succumbed to evil...
After Diablo's fall, Aidan had thought to contain the demon lord's essence within himself. While his intentions were noble, the Lord of Terror's oppressive will overwhelmed him.
My new comrades raced to Lut Gholein and learned of the Wanderer's plan to free Baal, the Lord of Destruction, from his prison beneath the nearby deserts. Yet they arrived there too late...
Baal's tomb was empty save for Tyrael, the archangel of Justice and a member of the Angiris Council, which ruled over the High Heavens. He too had learned of Diablo's journey east.
Tyrael implored the heroes to track down the two Prime Evils in the Temple City of Travincal and stop them from liberating their infernal brother, Mephisto, the Lord of Hatred.
Although the mortals followed Tyrael's guidance, the demon lords still succeeded in reuniting. It was then that Diablo assumed his true demonic form, shedding the last vestiges of Aidan's humanity.
Undaunted, my companions pressed on, slaying Mephisto and recovering his soulstone. They then pursued Diablo into the Burning Hells, where he had begun amassing his loyal demonic followers.
There, in realms where no mortal had trod, the fearless champions defeated the Lord of Terror. Upon the Hellforge, they sealed their victory by destroying the soulstones of Diablo and Mephisto.
With the heroes focused on his brethren, Baal marched an unholy army to Mount Arreat, site of the immense Worldstone. By corrupting this sacred artifact, he hoped to turn all of mankind to evil.
At the mount's summit, my comrades narrowly triumphed over the Lord of Destruction, but not before Baal had tainted the Worldstone. Humanity, it seemed, was doomed...
Tyrael believed that only one drastic act would spare mankind from damnation. And so he hurled his sword, El'druin, into the Worldstone, shattering the crystal and igniting a catastrophic explosion.
I cannot help but wonder what the price of Tyrael's action will be. Did he save our world, or did he merely consign it to some grim and unseen fate?
Despite the victories over the Prime Evils, I sense a darkness approaching. Two Lords of Hell remain--Azmodan and Belial--and I fear it is they who herald the coming End of Days.