During an outing with her husband Darinel and their dragon-friend Idunal, Princess Tuskja is attacked by a blue light and falls into a deep sleep. To cure her, Darinel and Idunal set out to find the Sea With No End. In its heart lies the underwater city of Aquaria where the last sea dragons live. These mystical creatures are said to have the Secret Green Waters, a potion strong enough to heal the curse of the blue light.
Sea dragons save the friends from almost drowning in their attempt to reach the city and bring them through the barrier into Aquaria. There, they meet beautiful Queen Ozeania, who ensnarls Darinel under her spell.
Banned from the palace for not trusting the queen, the dragon sets out alone to find the cure while Darinel forgets more of his past with each passing day. Have forged an alliance with the independent sea dragons, Idunal has to break the spell on Darinel and find a way to penetrate the barrier without breaking it in time to save Tuskja.