Here's the correct guide for the Thief-Catcher World Quest in Genshin Impact.
Unlocking the Quest 
1.Location: Mondstadt City
2.NPC: Speak to Cyrus, who is located near the Adventurers' Guild or sometimes wandering around Mondstadt.
Quest Walkthrough
3.Initiate the Quest: Talk to Cyrus. He will express concern over the recent increase in thefts and criminal activity by the Treasure Hoarders due to the chaos caused by recent events in Mondstadt.
4.First Encounter with Thieves: Cyrus will direct you to the first location where Treasure Hoarders have been spotted. This could be near the Whispering Woods or another noted area around Mondstadt.
5.Combat with Treasure Hoarders: Travel to the marked location on your map. Here, you'll need to defeat a group of Treasure Hoarders. They might be guarding some stolen goods.
6.Subsequent Locations: After dealing with the first group, Cyrus or another clue might direct you to additional locations where more Treasure Hoarders are causing trouble. Each location will involve combat.
7.Potential Locations: Near Springvale or around Wolvendom where Treasure Hoarders might be hiding out or setting up camps.
8.Retrieve Stolen Goods: Some encounters might involve retrieving stolen items. These could be in chests or dropped by the Hoarders after you defeat them.
9.Return to Cyrus: Once all designated groups of Treasure Hoarders are dealt with, go back to Mondstadt and speak with Cyrus again.
10.Quest Completion: Cyrus will thank you for your help in reducing the thief problem, possibly hinting at the need for continued vigilance or leading into another related quest.
Quest Rewards
•Adventure EXP: Approximately 100-200
•Mora: Around 15,000 to 20,000
•Primogems: 20 to 40
•Companionship EXP: If playing with a character who has a storyline or interaction in Mondstadt.
Quest Tips 
•Combat Preparation: Ensure your party has good synergy for dealing with multiple enemies. Pyro for shields, Cryo for speed debuffs, and Electro for reactions could be beneficial.
•Resource Gathering: Since you're exploring areas outside of Mondstadt, take the chance to collect local specialties like Philanemo Mushrooms or Windwheel Asters.
•Quest Tracking: Use the in-game quest tracker to keep an eye on your current objectives if you need reminders on where to go next.
•Co-op Mode: If you find the combat challenging or just for fun, this quest can be done in co-op mode, allowing friends to join in on the thief-catching action.
This quest not only helps in cleaning up Mondstadt's outskirts but also provides a bit of background on how the city's issues have ripple effects on its surroundings, enriching the game's world-building.
