In a tumultuous world of the Cold War, a mysterious Japanese submarine called "Ayu" embarks on a desperate mission as several nations begin reporting attacks from giant sea creatures. These monsters not only threaten the safety of the coastlines but also seem to be linked to an ancient artifact that has been discovered at the bottom of the ocean.
A brave team of sailors, led by Lieutenant Kuroda, faces unimaginable challenges as they descend into the depths to investigate. As their submarine ventures into the dark abyss, they encounter a submerged civilization that holds dark secrets and a tense relationship with the surface. The story revolves around the team's struggle to unravel the truth behind the attacks while dealing with betrayals within their own crew.
With stunning special effects of the time and a narrative that blends action, drama, and science fiction, the film takes us on an exciting journey filled with surprises. The confrontation between humanity and the forces of nature highlights the fragility of our existence in the face of the unknown. In the end, the team must decide whether to destroy the artifact to save the world or attempt to establish a connection with the creatures that have awakened from their slumber. An epic adventure that merges mythology and science fiction, leaving the audience captivated until the very last moment.