The violent hurricane is approaching the inland of Scotland. Rob (Robert Carlyle), the chief designer of the Thames Barrier, and his ex-wife, Sammy (Jessalyn Gilsig), the director of the sluice project, are called back to the sluice for safety inspections. Robert's estranged father, Professor Leonard (Tom Courtenay), has calculated and predicted based on his rich experience that once the flood hits, the Thames Barrier will be defeated. He promptly reported the situation to Ms. Nash at the crisis control center. However, his warning was not taken seriously. The experts at the crisis control center could not accurately judge the situation. The noncommittal Deputy Prime Minister promised people that the flood would not reach the city of London. The peak of the flood arrived in London three hours later. The raging waves jumped over the sluice gates, and hundreds of millions of tons of flood water rushed into central London, and in an instant it was a vast ocean. Millions of Londoners are in danger. Robert, Sammy and Leonard only have a few hours to save the city...