Kappa and Siren descend deeper into the darkness of the ocean and uncover the harrowing truths of their own destinies in this thrilling fourth installment of the hit Webtoon series Castle Swimmer . Kappa and Siren continue their thrilling journeys beyond the kingdom walls. Accompanied by his new companions Pim and Pagoon, Siren ventures into the shadowy ocean depths in search of a cure for his curse. Facing terrifying creatures that prey on their deepest fears and desires, the trio uncover more about Siren's prophecy and the darkness entwined with his fate. Meanwhile, Kappa continues to battle the great demigod crab with the last of the Octalia people, learning to harness his magical powers and grow his strength. Despite being on separate missions, Kappa and Siren remain connected through their unwavering dedication to each other, even if it is just an inflicted hallucination. Join Kappa and Siren as they bravely push forward into the unknown and face more mythical obstacles in this captivating continuation of the Castle Swimmer saga. This beautiful graphic novel collects episodes 66-86 of Webtoon's Castle Swimmer.