This story takes place before Rimuru's reincarnation. Shizu, also known as the Conqueror of Flames, responds to an urgent request calling her to the Kingdom of Filtwood. When she reaches the castle, many adventurers are already there. What request could have demanded such a huge gathering? It turns out a demon has been revived, and the adventurers have been called to subjugate it. It is said that more than ten of the most skilled adventurers have already been killed by this demon. But there is more to this request than meets the eye...
Makes sense, if it's possible 
someone could be possessed.
لا ألومهم. من الممكن أن يكون أحدهم ممسوساً
Weil alle besessen sein könnten.
Da bilden wir keine Ausnahme, Shizu.
Tiene sentido si alguno está poseído.
Tiene sentido si alguno está poseído.
Tout le monde peut être possédé,
et nous ne faisons pas exception !
In fondo c'è la possibilità 
che qualcuno sia posseduto.
Mas faz sentido, se alguém aqui
pode estar possuído.
Ведь демон мог вселиться в кого угодно!