Serving the Fates and Gods

Percy & Annabeth refuse to become immortal & flee the Gods domains. Decades later they are die as mortals. To Hades & Nico's surprise they are sent to the Isle of the Blest by the Fates. But now just a couple of years after their death they are needed again for another war. But how will they couple with the memories of ALL their lives together. How will the Demigods and Gods cope?