In *Kingdom Come: Deliverance 2*, a crucial side quest, easily missed and unrecoverable if failed, involves retrieving Rosa's book. This guide ensures you don't miss out.
Unlocking Rosa's Book Side Quest
Before Rosa requests the 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 to learn about a secret Maleshov passage for rescuing Hans. She'll then ask you to retrieve a specific book. Inquire about the book's details and agree to fetch it to initiate "Rosa's Book." This quest is only available during "Taking French Leave." Failing to retrieve the book before leaving with Hans permanently locks you out, preventing a potential romance with Rosa.

Locating Rosa's Book in Maleshov
Upon entering Maleshov, Hans is located in the tallest tower. Use the external stairs to access the tower. Inside, find another stairwell and a nearby kitchen. Wait in the kitchen until guards patrolling the upper levels leave.

Stealthily ascend the stairs to a room occupied by Lady Ofka. Knock her unconscious, and collect the keys from her person, the podium, and the sword from the chest. Rosa's book is in this room—a red book situated in a window alcove to the right of the fireplace. Grab it, updating your objective to returning the book to Rosa.

While there, acquire the sword from the chest in the adjacent room. This provides the two weapons needed for Hans and his unexpected guest, saving time later. Proceed to the top floor, unlock the left-hand door, and trigger a cutscene.
Completing the Quest
Following the cutscene, continue "Taking French Leave." Guide Hans to the stables, potentially advancing a romance by selecting the appropriate dialogue option (assuming you chose the heart option in Trosky). Clear the path to the stables, signal Hans, and ensure his safe arrival.
A final cutscene concludes the quest. Afterward, return to Kuttenberg City and deliver Rosa's book to Ruthard Palace, successfully completing this crucial side quest in Kingdom Come: Deliverance 2.