In *Kingdom Come: Deliverance 2*, a crucial side quest involving Rosa's book is easily missed, leading to a failed quest and potentially hindering your romantic pursuits. This guide ensures you won't miss out.
Unlocking Rosa's Book Side Quest
Before Rosa requests her book, complete "Via Argentum" and begin "Taking French Leave." After resolving the Vavak situation with the Ruthard family (through force or diplomacy), speak with Rosa. She'll reveal a secret passage into Maleshov, crucial for rescuing Hans. Inquire about the book and promise to retrieve it to initiate "Rosa's Book." This quest is only available during "Taking French Leave." Failing to find the book before leaving with Hans results in a failed quest.

Locating Rosa's Book in Maleshov
Upon entering Maleshov, Hans is in the tallest tower. Use the external stairs to enter. Inside, find another staircase and a small kitchen. Wait for guards to leave the upper levels.

Sneak upstairs and you'll find Lady Ofka. Knock her out, take her keys, the keys from the podium, and the sword from the chest. Rosa's book is a red book in the window alcove to the right of the fireplace. Grab it; your objective will update.

While there, take the sword from the chest in the adjacent room. This provides the two weapons needed for Hans and his guest, saving you time later. Unlock the door on the left on the top level to trigger a cutscene.
Completing the Quest
After the cutscene, continue "Taking French Leave." Guide Hans to the stables, neutralizing guards along the way. Once Hans reaches the stables, a final cutscene plays. Return to Kuttenberg City and deliver Rosa's book to her at Ruthard Palace.