Strike the Blood, Vol. 12 (light novel)

A hair-raising rescue! The sealing ceremony for the relic of The Cleansing has begun at last. But to everyone's surprise, the ceremony is disrupted by an incredible surge of magical energy triggered by Avrora, the former Fourth Primogenitor sealed within Nagisa. Her presence has caused the calamity sleeping at the bottom of Kannawa Lake to awaken...Caught up in the mix, Yuiri and Shio of the Lion King Agency venture out onto the frozen lake to rescue Nagisa-and find themselves facing off against draconic demon beasts! Meanwhile, Kojou and Yukina, who sank beneath frigid waters at the end of a fierce battle, wake up in a strange hot springs inn to find their wounds have completely healed.

At the root of it all is a mysterious girl named Glenda. Just who is she? And can she be trusted...?