The Witcher 3: Wild Hunt
78 Achievements
100-120h
The Doppler Effect
Resolve the doppler problem in Novigrad.
44.2%
How to unlock the The Doppler Effect achievement in The Witcher 3: Wild Hunt - Definitive Guide
You get this Contract Named An Elusive Thief (Level 13) in Novigrad from the Notice Board in Hierarch Square. Go to the Marketplace during Day and Talk to Sylvester Amello. Then use the Witcher Senses to the Thiefs House and follow his trail again.
If you let him live you get a good Diagram for a Weapon: Gnomish Gwyhyr Steel Sword (if you have hit Level 42 :D)
In order to unlock this achievement, you will need to complete the contract entitled “An Elusive Thief.” This contract can be triggered by picking up the "Contract: Imp" note on the notice board in Hierarch Square in Novigrad.
Once the contract is open, head over to the market area in Hierarch Square during the day and talk to the contract issuer. After speaking with him, use Geralt’s witcher senses to follow the red footprints on the ground and you will eventually reach a house where you will be required to pick up a letter. Read this letter and continue to follow the clues in this quest until you meet the Doppler. You'll have to fight him one-on-one and then you’ll have the option of killing him or letting him go. If you let him go (which is the recommended path) he will give you a fair amount of coins and a diagram for a Gnomish Gwyhyr. Now return to the market square and talk to the merchant to conclude the contract, receive reduced pay, and unlock this achievement.
*Missable Trophy*
This is missable if you let the doppler get away while chasing him on foot.
To unlock this trophy, you must complete the witcher contract "An Elusive Thief". It can be started at the quest board on Hierarch Square in Novigrad. From the quest board you must pick the note that says "Contract: Imp". "An Elusive Thief" will then start automatically.
Go to the market square at day and talk to the merchant. Now follow the red footsteps on the ground by using your witcher senses. You will reach a house where you must pick up a letter and read it in your inventory. Follow the trail of clues again and you will meet the Doppler. Chase him down and don't let him escape (if he escapes the quest will fail and you don't get the trophy). Defeat him in combat and you can choose to either kill him or let him go. For this trophy it doesn’t matter which option you choose. If you let him go he will give you a lot of coins and a diagram. If you kill him you can loot some items from his corpse. Return to the market square to talk to the merchant and the trophy will unlock.
You can skip it!!!
Order: Elusive Thief (taken from the notice board in Novigrad). As soon as you find the Doppler, after dialogue with you he will begin to run away. You need to catch up with him (click next to him), if he runs away, the quest will fail, and with it the trophy Geralt: The Professional / Master Witcher will be unreachable.
Video for clarity.