Payback is a main quest in Novigrad and part of Final Preparations. Ciri spent some wild times in the city, and now that she is back, she wants to thank some people and have a word with others. Geralt comes along for the ride.
The first name on her list is Whoreson Junior. What happens here depends on what Geralt did at the end of Get Junior. If Geralt swore he killed Junior, rumour has it that the crime boss is somehow alive and well, and a surprise visit reveals that Dudu has turned Junior’s death into a business opportunity by taking on his identity. If Geralt spared Junior, the story plays out differently.
From there, Ciri and Geralt visit other places and people she remembers from her time in Novigrad, including the Golden Sturgeon and the elven quarter of Farcorners. It is a light, character-driven quest that shows how much Ciri has grown and how she treats the people who helped or hurt her.