
The protagonist, Artel, and her husband Kaale are a newlywed couple.
The two of them begin an investigation of a dungeon located in a secluded mansion as part of a request they accepted.
One day, while progressing through the investigation, the client tempts Artel by saying, “There’s an easier way to explore the dungeon.”
When she listens to the method, an unfamiliar “mysterious pattern” suddenly appears on her abdomen.
Though the pattern seems to be deeply affecting her mind, Artel continues the exploration in order to complete the request…