Tearmoon Empire: Volume 15 by Nozomu Mochitsuki

First, a horsemanship tournament to save Ruby from her engagement to Hildebrandt, and then a cooking party to prevent Sapphias from staging a coup—Mia’s been busy this summer! But it’s not time for her to rest quite yet. Having come face-to-face with Gerta, Patty is despondent and desperate to see her brother. Thus, Mia resolves to take her to the former Clausius domain...and this time, Emperor Matthias decides to come along. It’s a family trip!

But when Patty finally comes face-to-face with the truth, what will become of her? Will she be freed from the Serpents, or will she only fall further into their clutches...?