Thirty years ago, the ocean-going cargo ship "Breaking Waves" mysteriously lost contact in the "Blue Forbidden Zone". The logbook left by the captain Jiang Zhenhai became the only clue for the Jiang family. The lines are full of strange descriptions such as "deep sea whispers", "scale-claw shadows" and "indescribable spirals". Thirty years later, Jiang Jiahao took over the family salvage company that was on the verge of bankruptcy. In order to repay huge debts and solve the mystery of his grandfather's disappearance, he formed a temporary team and drove the refurbished "Pursuit" into the blue waters classified as restricted areas by the International Maritime Organization.
The ocean here is a strange dark blue, the compass is malfunctioning, communications are interrupted, and there are rusted shipwrecks and twisted remains of marine life floating on the sea surface. As the "Pursuit" penetrated into the restricted area, the crew began to have hallucinations: some heard whispers from the bottom of the sea, some saw human silhouettes covered with scales flashing outside the ship's side, and Jiang Jiahao himself frequently dreamed of his grandfather struggling in the spiral cave. When they found the wreckage of the "Breaker", they found that the interior of the hull was covered with spiral patterns, and there were inhuman claw marks on the deck. On the last page of their grandfather's diary, there was a bloody arrow pointing to the deep sea trench.
