Season 1

On the coast, Marion Wienesse witnesses a kitesurfer's accident when a violent gust drives him into an apartment block. Prime Minister Hans Kreuger attends the ceremony for renowned violinist David Stein, who has withdrawn from public life after his wife's death, when he is urgently summoned to the command center. In Belgium, the Prime Minister orders evacuations in parts of West Flanders, including Ostend, as the Spuikom threatens to overflow under an imminent storm. The Dutch government, like him, issues a warning to the population about the danger of flooding. Robert Wienese is having an affair with a female colleague and seeks a divorce, increasing tension within the family. Their home is overwhelmed by news from the Internet and television about the storm. The command center debates whether the Randstad should be evacuated for a possible flood; a breach of the dikes would unleash an incalculable disaster on the Netherlands, yet evacuation could cause severe economic damage and imperil the governing coalition. In Rotterdam, the Belgian family Van Daele visits the father of the family in prison, who is detained on a manslaughter charge, a few days before the birthday of their youngest daughter Femke. When the family must leave, Ronnie becomes aggressive and must be sent to a shelter. They return to Ostend, where a massive evacuation is underway, but decide to go home because their grandmother remains. They refuse to leave the house for a shelter. A few days later the storm intensifies. Kreuger urges his wife to move to safer places, although danger remains uncertain. She defies his protests and goes to her father's retirement home to fetch him and depart. A nurse photographs the scene and posts it online, triggering panic throughout the Randstad and causing long traffic jams. The Wienese family decides to leave. Father Robert witnesses his mistress being swept away by a large road sign and dies. Upon returning home his wife has already packed all suitcases and left. In Belgium Femke's birthday approaches. Manu, a family friend, is present. The two children Sonja wants to play outside, but she initially hesitates and, urged by Manu and Grandma, she agrees to go out. In the command center the tension runs high; no one knows whether the levees will hold. The Prime Minister sends a message to seek higher ground while thousands are still in cars beneath sea level. Then the levees break and the country floods rapidly. In the command center officials can only watch in despair. In Rotterdam, Stein contemplates ending his life because he cannot cope with loneliness after his wife dies; he sits in the bath with a razor. Just before he acts, the doorbell rings. A little girl stands in the flooded streets of Rotterdam and asks to come inside. The old violinist takes her upstairs, realizing he cannot leave her there. Ronnie experiences water entering his space as well. In Ostend Manu hears a huge wave approaching and calls the children indoors. Femke does not listen and attempts to reach the birthday boat given by her father; the rising water carries her away.