Brothers in Arms: Novigrad is one of the recruitment quests that Geralt can complete before The Battle of Kaer Morhen. A direct fight with Eredin and the Wild Hunt is unavoidable now, and Geralt knows he cannot win it alone, so his first stop is Novigrad, where he has more friends than anywhere else.
The results depend on earlier choices. Zoltan Chivay is always ready to help an old friend. Vernon Roche and Ves of the Temerian partisans can join if Geralt has helped them, which may mean finishing An Eye for an Eye. Triss comes if Geralt helped her save the mages of Novigrad in Now or Never, and Dijkstra may offer men or money instead of fighting himself.
The conversations are short, but they show how far Geralt’s reputation has spread and how many people are willing to risk their lives for him and Ciri.