Undetected Infiltration is one of the world quests Genshin Impact that was added during the 2.7 version update of the game. It is one of the quests that adds detail and story to the region in Liyue called The Chasm.
During this quest, you will help a Millelith Squad take care of a group of Treasure Hoarders doing illegal business in the mines. This side mission is also connected to two other quests in the game that interconnect with it.
How to Unlock the Undetected Infiltration World Quest
To unlock this world quest, you need to do the Chasm Delvers world quest series until the second sub-quest, Surreptitious Seven-Star Seal Sundering, where you will need to destroy three Bedrock Keys.
One of the said Bedrock Keys is situated above a miner’s warehouse or shed west of the Teleport Waypoint in Tiangong Gorge. Treasure Hoarders will lurk about in that shed and attack you when you go near the area.
After defeating the wave of enemies, one of them will try to talk to you to explain the situation. This person will introduce himself as Yanbo, a Millelith Squad Leader of The Chasm District. They took care of the Treasure Hoarders stationed in this old warehouse used as their lair and disguised themselves to gather intel about the bandit’s activity in the Chasm. They were also protecting the Bedrock Key in the area to prevent people with bad intentions from ever touching it.
Yanbo will then reveal that one of the Treasure Hoarder leaders is in contact with a branch of the Fatui and that they may be preparing a transaction involving dangerous items. He will ask for your help in catching the group of Treasure Hoarders in their camps around The Chasm.
This will trigger the world quest, which will be available in your quest window. Do the following steps below to complete this world quest and obtain the rewards.
1. Meet up with Yanbo in front of the smuggler’s camp.
The location is in Lumberpick Valley, which is northeast of The Chasm.
You will find Yanbo on a wooden platform, waiting to discuss their plan and instructions for the mission with you.
The Treasure Hoarder smugglers should be undertaking their transaction with the Fatui in the large encampment east of your current location. They also have set up three smaller camps along the way. The smaller camp to the southeast is believed to be cooking quarters, the one further east is the weapon stash, and the northeastern base is an alchemy camp.
Yanbo suggests taking the three smaller camps by surprise to cut off the smugglers’ supply line. The previous incident with the Jade Chamber had the Millelith do fewer patrols in the area, making the Treasure Hoarders slacken their guards significantly. This gives Yanbo’s team a chance to strike.
The Millelith Squad Leader will then ask your suggestion as to which camp to take down first. Choose one of the three to proceed with the mission.
2. Clean out the Treasure Hoarder logistic camps. (3/3)
After selecting which camp to take down first, the one you chose will automatically be taken care of. You will now have to hit the remaining two smaller camps, which will be marked on the map.
3. Defeat the Treasure Hoarder smuggling crew at the larger camp.
After clearing out the Treasure Hoarders in both camps, go to the larger camp and defeat the Treasure Hoarder smugglers there.
This camp is located east of the Teleport Waypoint in Lumberpick Valley.
You will need to defeat several waves of enemies in this camp, both Treasure Hoarders and Fatui members.
The first group you will face is a Treasure Hoarder Crusher, a Fatui Cryo Cicin Mage, and a Fatui Pyro Agent.
After defeating these enemies, three waves of bandits will appear to attack you. You will have to fight two groups of 4 Treasure Hoarder Scouts and a group of 4 Treasure Hoarder Handymen.
Following that wave of Treasure Hoarders, you will have to face the two boss smugglers.
The first one is Brass Bull Zhao—How Is a Wild Bossy Not a Heroine?—who uses an ax to attack.
The second boss smuggler is Chen the Flower—A Flower Can Still Be a Real Man—wields a hammer just like a Treasure Hoarder Crusher.
Once defeated, Yanbo will appear in his Millelith uniform to thank you and hand over your reward for helping his squad.
Aside from the quest reward, a Precious Chest will appear in the camp, and one of the treasures you will get inside is the Cup of Commons.
This item is one of the six lost offerings scattered throughout The Chasm. It is one of the things you need to gather to complete the quest of The Millennial Mountains.
Quest Completion Rewards:
After completing this world quest, you will unlock and earn the following:
Obtain reputation points and mark off one of the items on the Liyue Quests Completion Progress list.
Unlock the Achievement. Well Done, Stierlitz! – Help Yanbo complete Millelith’s mission.