While on a quest to assist Aquaman, Garth was kidnapped and forced to fight a giant sea beast to the death, surviving just long enough for Aquaman to defeat the monster. Little did Garth know that, before long, he would be forced to defend himself in a life or death struggle against his mentor over the survival of the infant Arthur Jr. (AKA "Aquababy"). Betrayed and abandoned by Aquaman, Garth stayed in the Hidden Valley to search for links to his identity, eventually finding out he was the lost prince of the Idyllists, though it would be several more years before he learned the truth about his father's murder and his mother's complicity in his exile at the hands of the Poseidonians.