Seventeen-year-old Gen may have rescued her beloved father from prison, but she hasn’t saved him yet. If she fails her end of a bargain with the Olympian Empresses, they will send him right back to his cell. To keep the Empresses happy, Gen must bring them the legendary golden apples of Hesperides and the monstrous Cerberus. But both are rumored to be in the neighbouring Elysium Empire, which has a long history of war with Olympia. Making matters worse, Gen’s former enemy and newly designated heir to the isle of Arcadia Castor invites herself on the journey, hoping a golden apple could end Arcadia’s reliance on Illumium for storm vials. And Castor’s twin brother, Gen’s StormMaker boyfriend Pollux, has been pulling away from Gen due to troubles stemming from her mind magic.