In *Kingdom Come: Deliverance 2*, missing certain side tasks can lead to failing them with no chance to return, and Rosa's book quest is one such task. To embark on this side quest, you first need to complete the "Via Argentum" quest and initiate "Taking French Leave." After assisting the Ruthard family with Vavak, you'll be directed to speak with Rosa. She'll inform you about a secret passage into Maleshov to rescue Hans and will request you to retrieve her book while you're there. Engage with her about the book and commit to bringing it back to start the "Rosa's Book" side quest.
Screenshot by The Escapist
You can only complete this quest during "Taking French Leave." If you leave with Hans without securing the book, the quest will fail, and you'll miss the opportunity to romance Rosa. Fortunately, the book is conveniently located on your path to Hans' room.
Upon entering Maleshov, head to the largest tower where Hans is located at the top. Use the side stairs to reach the entrance, then sneak inside. You'll see another set of stairs and a small kitchen nearby. Hide in the kitchen until the guards upstairs leave the tower.
Screenshot by The Escapist
Next, stealthily ascend the stairs to find a room with Lady Ofka seated by the fireplace. Sneak up behind her, knock her out, and take the keys from her body and the podium, as well as the sword from the chest in her room. In this same room, you'll find Rosa's book to the right of the fireplace, placed in a window alcove. Pick up the red book, and your objective updates to return it to Rosa.
Screenshot by The Escapist
While in the vicinity, grab another sword from the chest in the adjacent room to save time when meeting Hans, as you'll need two weapons for him and his unexpected guest. Then, proceed to the top level and unlock the door on the left to trigger a cutscene.
Following the cutscene, continue with "Taking French Leave." Although Hans refuses to use the passageway, you can advance towards romancing him by choosing the dialogue option with a heart symbol, provided you made the same choice in Trosky. Sneak to the stables on the north side of Maleshov, neutralizing and hiding guards as necessary. Once the path is clear, signal Hans to ensure his safe passage to the stables.
After opening the gate and completing another cutscene, you'll conclude the quest. Then, return to Kuttenberg City and visit Ruthard Palace to deliver Rosa's book, fulfilling your promise in *Kingdom Come: Deliverance 2*.
