In 2025, construction of the Shenzhen-Zhongshan Link disturbed the seabed at the mouth of the Pearl River, awakening the “Coral Tears,” a sealed Japanese military compartment from World War II. Mutated luminous algae sparked a “Ghost Red Tide” that began devouring the bridge piers. Hai Kui, a descendant of the Tanka people and a doctoral student in molecular anthropology, can read genetic memories by touching ship timber. From the ship-burial remains exposed by the construction, she glimpses the secret history of Ya Gu, a mute girl who fought back against the Japanese with toxic algae in 1943.
Hai Kui's biological father, construction magnate Chen Yuan, launches an acoustic algae-eradication system to save the project, unaware that it will endanger the Tanka people who live in symbiosis with the algae. Lu Jun, a cross-border environmental leader and modified human with implanted artificial gills, intercepts a sample of the “Coral Tears” and discovers that it is a living weapon created from Ya Gu's genetically altered DNA. As the investigation deepens, the truth of 1943 emerges: forced to cultivate luminous algae for the Japanese, Ya Gu secretly implanted toxin genes. The Tanka people sealed the poisonous algae inside a shipwreck, creating the ship burial.
The modern crisis worsens: a genetic map appears on Hai Kui's palm, pointing to an antidote; Chen Yuan infects Lu Jun's artificial gills with a virus; and Ya Gu's symbiotic algae manifest as a consciousness within the red tide. Chen Yuan also discovers that his allergy to seawater stems from his origins as an abandoned Tanka child. As the red tide engulfs Shenzhen Bay, Hai Kui leads the Tanka people in building a biological computer from boat coffins. Lu Jun plunges into the algae, sacrificing himself to upload the neutralizing gene.
In the end, the ship burial becomes the 2079 refuge known as Bone Boat Island. Chen Yuan's skeleton gives rise to fluorescent coral, while Lu Jun's consciousness merges with the ocean's neural network, bringing sea and land into a peaceful symbiosis.
