 Dion’s wife, Arete, and sister, Aristomache, discovered the Callippus’s plot against Dion, but Dion was still paralyzed with remorse from his son’s death, and refused to take action.Arete and Aristomache further inquired about the plot against Dion, and when Callippus discovered their inquisitiveness, he approached them and told them that he was loyal, and that he would prove his loyalty.They told him to take the Great Oath, involving a ceremony in Persephone’s temple, which he took.