In *Kingdom Come: Deliverance 2*, missing out on certain side tasks can lead to failure since you can't return to them. One such crucial side task is finding Rosa's book. To help you navigate this, here's a detailed guide on how to unlock and complete the "Rosa's Book" side quest.
Unlocking the Rosa's Book Side Quest
To start "Rosa's Book," you first need to complete the "Via Argentum" quest and begin "Taking French Leave." During "Taking French Leave," you'll assist the Ruthard family in dealing with Vavak, either through force or persuasion. After resolving this, you'll be directed to speak with Rosa. She'll reveal a secret passage into Maleshov that you can use to rescue Hans. In the same conversation, Rosa will ask you to retrieve a specific book for her. Make sure to ask her about the book and promise to bring it back to her, which will officially start the "Rosa's Book" quest.
Screenshot by The Escapist
Remember, this quest can only be completed during "Taking French Leave." If you leave Maleshov with Hans without finding the book, the quest will fail, and you'll miss the opportunity to romance Rosa if that's your goal. Fortunately, the book is conveniently located on your path to Hans' room.
Finding Rosa's Book
Upon entering Maleshov, head towards the largest tower where Hans is located at the top. Use the side stairs to access the entrance. Once 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
Sneak up the stairs to find a room with Lady Ofka sitting by the fireplace. You can quietly approach her from behind and knock her out. After neutralizing her, take the keys from her body, the keys from the podium in her room, and the sword from the chest. In this same room, you'll find Rosa's book. Look to the right of the fireplace, where you'll see a red book in a window alcove. Pick it up to update your objective to return the book to Rosa.
Screenshot by The Escapist
While you're in the area, don't forget to grab another sword from the chest in the next room. This will save you time later when you meet Hans, as you'll need two weapons for him and his unexpected guest. After collecting everything, 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 may not want to use the passageway, you can work towards romancing him by choosing the dialogue option with a heart, provided you made the same choice in Trosky. Next, sneak to the stables on the north side of Maleshov, knocking out and hiding guards as necessary. After clearing a path, signal Hans and ensure his safe passage to the stables.
Open the gate, and you'll enter another cutscene, marking the end of the quest. Once it concludes, head back to Kuttenberg City and stop by Ruthard Palace to deliver Rosa's book in *Kingdom Come: Deliverance 2*.