Echoes of Yesterday
You can trigger this quest by speaking to Yaevinn in the Druid’s Grove. If you’ve completed the Gold Rush quest then Echoes of Yesterday will no longer be available.
Yaevinn says that he sent a group of elves and dwarves in the Sewers (Trade Quarter) to find the Elven Ruins. Make your way into to the Sewers and then head towards the eastern side where you’ll find the Elven Ruins. Talk to the dwarf called Ren Grouver who’ll tell you about a beast killing everyone in sight.
Enter the ruins and kill the Bruxa (a kind of vampire). Ren will run in and thank you for your help and Yaevinn will teleport in from the nearby portal and give you your reward of 300 Orens. You’ll also earn 7,000 experience from this little adventure.
Back: The Witcher Chapter 3