This episode starts with Yomi and Kagura trying to destroy a "Category B" evil spirit that can create clones of its opponents. The heroines have a difficult time killing it, until Mei appears and helps them finish it off. After the battle, Mei tells the other exorcists that they should be more diligent, and implies that Yomi is not strong enough to handle her responsibilities.
Later, Kagura gets her leg bandaged by her school's nurse, and gets teased by a couple of her friends for it. When she returns home, her father reminds her that she has to be strong, as she will one day inherit his spirit beast for herself.
Meanwhile, Mei tries to track a particularly strong spirit, and meets a white-haired boy who tells her about the "sesshouseki" or "Death Stone" and its power to awaken evil spirits. Mei tries to attack the boy, but her weapon doesn't appear to have any affect on him. The boy then takes her own weapon and thrusts it through her chest.
Back at the school, Kagura's friends are finishing up their after-school club and end up spotting a bloody incident. Without stopping to see the attacker, they try to run and hide in a locker instead. Kagura manages to arrive in time to save them, only to find out that the attacker is a "Category D" spirit that has possessed the nurse who bandaged her wound. After repeating her exorcist mantra, Kagura finds the courage to kill the posessed nurse, though her friends later see her holding the bloody sword.