An infectious disease researcher is on a cruise with her daughter when an ebola-type virus attacks the ship's passengers and crew.

The busy epidemic expert Dr. Stephanie Tauber wants to take time for her daughter Aly during a Caribbean cruise. But when a series of mysterious deaths occur on board, the vacation is over. Dr. Tauber has samples brought to the laboratory of her boss Dr. Norman Ellisy from the "Center for Disease Control". It turns out that a previously unknown, deadly virus is rampant on the "Orion Star". Dr. Tauber is given command of the ship, which is forcibly quarantined in the sea off Miami. In a desperate race against time, she tries to develop a serum. The snubbed captain needs some time to come to terms with the new situation and tries desperately to prevent panic on board. But more and more deaths occur. A passenger throws herself from the deck, a fleeing couple is shot by the coast guard. The US President still believes that Dr. Tauber will be successful. Meanwhile, his advisor Henry Northcutt is planning a diabolical intrigue. In order to thwart the liberal politician's re-election, he is stirring up the crisis and wants to persuade the president to sink the "Orion Star" out of alleged concern for the country. The situation then escalates dramatically: Dr. Tauber's daughter Aly is dying and the engineer McBride (Michael Ironside) has incited parts of the crew to mutiny in order to escape from the "Orion Star", which has been anchored for a month. When Dr. Ellisy announces that he wants to bring a healing serum on board, it is almost too late.—ADR Das Erste