As an avid traveler in Teyvat, I recently embarked on the fourth installment of The Chasm Delvers questline, "Heavenly Stone's Debris," which presents a thrilling challenge centered around locating two crucial security keys. This quest unfolds in the mesmerizing Underground Mines of The Chasm, a region teeming with ancient mechanisms and the formidable Ruin Serpent boss. Before diving into this adventure, players must complete three prerequisite quests: "The Chasm Charters," "Surreptitious Seven-Star Seal Sundering," and "Chasm Spelunkers." Once prepared, the journey begins by conversing with Jinwu, the knowledgeable NPC responsible for enhancing the Lumenstone Adjuvant gadget. She reveals that accessing the gunpowder storehouse requires two hidden keys scattered across the treacherous depths.

🔑 Locating Security Key No. 1

My first stop was the Teleport Waypoint north of the Underground Waterway. From there, I navigated toward a water-filtration device opposite a Treasure Hoarder campsite. A critical tip: ensure your Lumenstone Adjuvant is upgraded to at least level 2, as the area is engulfed by potent Dark Mud. Using the gadget's luminescent power, I cleared the obstruction, revealing a breakable pot atop the device. Smashing it uncovered an Investigation spot, rewarding me with Security Key No. 1. This step emphasizes the importance of gadget preparation—neglecting it could halt progress entirely!

🔑 Hunting for Security Key No. 2

For the second key, I returned to the same Teleport Waypoint but glided northeast into a cavernous dip. A bridge guarded by Oozing Concretions came into view—a sight that demanded caution. I opted to glide from the bridge's left side toward a group of Treasure Hoarders, where a trail of footsteps led to a Dig spot. Interacting with it spawned an explosive Geo barrel; destroying the barrel unveiled another Investigation spot, granting Security Key No. 2. Along the way, I noticed a swirling passage to the right of a tent with a "Move Up" prompt. Curiosity led me to a caged area containing a Luxurious Chest and a lever. Pulling the lever not only opened the gate but also unlocked the hidden achievement "All We Need Is Some Firewood and Some Vinegar…"—a delightful bonus!

💎 Key Takeaways and Tips

• Prerequisite Check: Verify completion of prior quests to avoid accessibility issues.

• Gadget Upgrade: The Lumenstone Adjuvant's level 2 capability is non-negotiable for Dark Mud clearance.

• Exploration Rewards: Always investigate side paths; they may yield achievements or rare chests.

This quest not only advances The Chasm's narrative but also immerses players in intricate exploration mechanics. With both keys secured, I proceeded deeper into The Chasm, eager to uncover more secrets. For fellow travelers undertaking this mission in 2025, remember that patience and attention to environmental details are your greatest allies!