Autumn is just around the corner, and it's finally time for Forge Eizo to build a bathhouse! Blacksmithing is exhausting, sweaty work, so who wouldn't want a natural hot spring to soothe away the aches of the day? As the family begins construction, Eizo realizes he doesn't have a way to contact his friends outside of the Black Forest—it's not like texting has been invented yet. Right on cue, Camilo proposes a solution to this problem, but it comes with a catch: Eizo must take in another apprentice. Enter Karen Katagiri from the Nordic region! Eizo prays that Karen doesn't press him about his fake backstory, but as he gets to know her, he can't help but feel that something is amiss... Are her intentions as pure as the steel she wishes to forge? Or will she thrust a dagger into the heart of Eizo's family?