The British government invites Finn Shepard, the hero who fights sharknadoes, to attend a high-level meeting on sharknado resistance. But his friend Nova urgently contacts him to go to Stonehenge to explore the secret of human ancestors' resistance to sharks. The two obtained the artifact in the mysterious cave, but they did not expect to trigger a large-scale storm. Countless sharks fell from the sky, and disasters occurred one after another around the world. Finn and Nova hurried back and fought side by side with his half-robot wife April and youngest son Jill. However, the storm was too fierce, and Nova failed to protect Jill, causing him to be swept into the storm. Finn and April were anxious and tried every means to enter the storm to rescue their son. They were taken to Switzerland, Australia, Brazil, Italy and Japan by the storm, and everywhere they went was full of grief and chaos. At this time, the sharks that were mutated by nuclear waste contamination at sea became more and more ferocious, and Finn's family and friends died one after another, and bad news came one after another. Where will the heartbroken couple go, and how will they stop the disaster from continuing?