To make Helen stronger, Seiichi and his group decided to delve into a dungeon. However, at the same time, Destra, known as "Suredeath" and a "God Apostle" of the Demon God Cult, who possesses the deadliest abilities capable of killing everything, is also challenging the same dungeon. Meanwhile, Helen's hometown is threatened by an ominous force even as they undertake their dungeon quest. This is the tenth installment of the popular isekai fantasy series, characterized by its blend of tension and comic relief!