Saito, who was summoned as a familiar to the parallel world of Halkeginia, is still treated like a dog by his owner Louise. One day, Princess Henriette summons a girl because of an incident where she repulsed an enemy army. She is concerned that Louise's ability to control the legendary element Void will not become widely known, because then enemies will pursue the girl. The childhood friend again swears devotion to the Princess, and Saito is forced to promise that he will help his mistress. However, Henriette, who looks as if everything has finally calmed down, is actually despondent, believing that her beloved Prince of Wales has died. Using her affairs of the heart for their own purposes, the enemy army of the Reconquista sets their machinations in motion... A love and dramatic story playing out in a parallel world - the fourth volume!