In *Kingdom Come: Deliverance 2*, a crucial side quest, easily missed and impossible to replay, involves retrieving Rosa's book. This guide will show you exactly how to find it.
Unlocking Rosa's Book Side Quest
Before Rosa requests your help, complete "Via Argentum" and begin "Taking French Leave." After assisting the Ruthard family with Vavak (through combat or diplomacy), speak with Rosa. She'll mention a secret passage to Maleshov, vital for rescuing Hans. Inquire about the book she needs, and agree 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 and prevents 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's entrance. Inside, find another stairwell and a small kitchen nearby. Wait in the kitchen until the guards upstairs leave the tower.

Sneak upstairs. You'll find Lady Ofka in a room. Knock her out, and collect the keys from her, the podium, and the sword from the chest. Rosa's book is in this room—a red book in the window alcove to the right of the fireplace. Take the book, updating your objective to return it to Rosa.

While there, take the sword from the chest in the adjacent room. This saves time later when equipping Hans and his unexpected guest. Proceed to the top floor, unlock the left door, and trigger a cutscene.
Completing the Quest
Following the cutscene, continue "Taking French Leave." Guide Hans to the stables, neutralizing guards along the way. After the final cutscene, return to Kuttenberg City and deliver Rosa's book to her at Ruthard Palace.