As the party continues at the Moriya Shrine, Reimu is convinced to tell her part of the story of the Scarlet Mist Incident. When she found out about the scarlet mist, she quickly arrived to the Scarlet Devil Mansion, easily defeating Rumia and Meiling in the way. When she enters the Mansion, she encounters Sakuya, who demonstrates to be a strong enemy using her abilities of time control, but Reimu still found the way to defeat her. As Marisa keeps battling Patchouli; Flandre, who is still caged in a water prison, remembers all the times she has been left aside by her older sister. When Patchouli is defeated, Marisa convinces Flandre to confront Remilia along with her. Flandre gathers enough courage to talk back to her sister, and summons a fire sword (possibly Laevateinn). Remilia turns to her little sister and accepts her challenge.
这一集以灵梦的角度讲述她在异变当天的征途。先是在雾之湖绕过了露米娅，然后在红魔馆大门对战门卫红美铃。经过马拉松式的艰苦战斗，灵梦击败美铃进入宅邸。博丽巫女在洋馆大厅遭遇十六夜咲夜，这是她们第一次相遇。尽管咲夜是一个强大的对手，但灵梦还是找到了制服她的方法。
另一边，芙兰朵露回想起自己被姐姐幽禁的岁月。在魔理沙的带领下，她鼓起勇气向蕾米莉亚争取自由。
片尾曲为「夜桜に君を隠して」（原曲：东方红魔乡第二关背景音乐「ルーネイトエルフ」）。
