Akara will grant you this quest upon completion of the Sisters' Burial Grounds. Akara informs the player of a Horadrim sage named Deckard Cain, whom she believes will be able to advise the Rogues on their present situation. Cain can be found in the town of Tristram; however, the journey is too far on foot, so the only feasible way to travel to Tristram is via the magical portal opened within the circle of Cairn Stones located somewhere in the Stony Field.
The only way to activate the Cairn Stones is to touch each stone in a specific order. The proper order can be found within the runes on the bark of the sacred Tree of Inifuss, which must be brought to Akara for translation.
After Akara has translated the runes, return to the Stony Field and locate the Cairn Stones. The stones are guarded by a Super UniqueCarver named Rakanishu. Using the Scroll of Inifuss as a guide, touch each of the Cairn Stones in the correct order to open a portal directly to Tristram. Deckard Cain can be found near the well in the center of Tristram, guarded by several Champion monsters. It should also be noted that both Griswold and Wirt can be found here as well, however, neither are what they once used to be.
Following his rescue, Deckard Cain will offer to identify items at no charge. Akara will also reward you with a random ring (magic in Normal, rare in Nightmare and Hell).
If Deckard Cain is not rescued before continuing to Act II, it will be considered a failed quest until a new game has been made. In this case, Deckard Cain will be rescued by the Rogues, and charges a fee of 200 gold per identified item.
It is clear that we are facing an Evil difficult to comprehend, let alone combat. There is only one Horadrim sage, schooled in the most arcane history and lore, who could advise us...His name is Deckard Cain. You must go to Tristram and find him, my friend. I pray that he still lives.
Tristram is too far to journey by foot...Cain would likely be dead when you arrived. However, there is a magical portal that will take you there instantly. To open it, one must stand within the circle of Cairn Stones and touch them in a certain order. The proper order can be found in the runes written on the bark of the Tree of Inifuss. You must find the sacred Tree of Inifuss and bring back its bark. I will translate the runes to unlock the Stones' mystic pattern.
Regrettably, I could do nothing to prevent the disaster which devastated Tristram. It would appear that our greatest fears have come to pass. Diablo, the Lord of Terror, has once again been set loose upon the world!
As you know, some time ago Diablo was slain beneath Tristram. And when our hero emerged triumphant from the labyrinth beneath town, we held a grand celebration that lasted several days.
Yet, as the weeks passed, our hero became increasingly aloof. He kept his distance from the rest of the townsfolk and seemed to lapse into a dark, brooding depression. I thought that perhaps his ordeal had been so disturbing that he simply could not put it out of his mind.
The hero seemed more tormented every passing day. I remember he awoke many times - screaming in the night - always something about 'the East'.
One day, he simply left. And shortly thereafter, Tristram was attacked by legions of foul demons. Many were slain, and the demons left me to die in that cursed cage.
I believe now that Tristram's hero was that Dark Wanderer who passed this way before the Monastery fell.
I fear even worse, my friend...I fear that Diablo has taken possession of the hero who sought to slay him. If true, Diablo will become more powerful than ever before.