Brothers in Arms: Nilfgaard is the shortest of the recruitment quests before The Battle of Kaer Morhen. Geralt knows the coming fight against Eredin will be the hardest of his life, and this time the stakes are bigger than him: Ciri’s life, and possibly the whole world, depend on it. Extraordinary circumstances call for extraordinary measures, so he goes to Vizima to ask the Emperor of Nilfgaard for help.
The audience at the Royal Palace does not go the way Geralt hoped. Emhyr has his own conditions, and Geralt is not willing to accept them. Two very strong wills clash, and neither side backs down. Geralt walks away empty-handed.
The quest has no reward and no ally at the end, but it is a telling scene. It shows how differently Geralt and Emhyr see Ciri: one as a daughter to protect, the other as an heir to secure.