The World He Knew is part of the Diablo 4 season three questline, and it introduces players to the mechanic that lets them craft and construct various stones for their Seneschal Companion.
The Seneschal Companion is a mechanical construct that becomes your faithful ally early on in the season’s questline, and it can be outfitted with Governing and Tuning Stones that equip it with special abilities and augments. While these stones are primarily acquired by completing Arcane Tremors and Vaults, they can also be crafted.
By completing The World He Knew, you can unlock the ability to craft these stones during Diablo 4 season three.
The World He Knew quest requirements
To start The World He Knew, you need to complete the first six quests of the Season of the Construct main questline, starting with A Supparated Wound and ending with The Smothered Ache. During these quests you will discover and complete different vaults and also become familiar with the seasonal activity Arcane Tremors.
Once you turn in The Smothered Ache to Ayuzhan at the new Gatehall hub, you will automatically start The World He Knew.
How to complete The World He Knew
To complete The World He Knew, you will need to have reached at least level 20 with your character, since you need the Jeweler to complete the first part. Talk to The Cofferer, a jeweler construct in The Gatehall, and craft one Uncertain Seneschal Stone Cache, which costs 200 Shattered Stone and 20 Iron Chunks. At this point in the questline, you should easily have enough Shattered Stone from defeating constructs.
Next, head to the Caldeum Library by way of the Imperial Library waypoint. Interact with the three ritual scrolls and then head to the quest marker in Gea Kun to attune the runestone by interacting with the Terror pit.
Then, go receive the Blessing of Diablo in Chambatar Ridge, which is accessible by teleporting to the Fate’s Retreat waypoint. After receiving the Blessing, return to the Gea Kul waypoint and head north to find the Vizjerei outpost, which is on the western edge of the quest circle.
You’ll have to complete the Vizjerei Athenaeum dungeon to finish The World He Knew, but it’s more of a single bossfight than a full dungeon. You’ll have to defeat a teleporting elite Defender of the Vizjerei first, before defeating the much tougher elite Risen Vizjerei. You’ll just need to stay out of range of its AoE attacks and chip away at its health. Interact with the Vizjerei Altar on the wall to seal the Hell-Blessed Runestone and complete the quest, and earn another Uncertain Seneschal Stone Cache.
