On a plane bound for Los Angeles from Hawaii, passengers begin to fall ill die from a viral infection. Dr. Robert Haines, a coroner on board the flight, has a strong sense of what is going on and has the pilot make contact with the Center for Disease Control field office in Los Angeles. The top scientist there, Dr. Laura Chadwick, and a team from the National Security Agency take over the job of bringing the passengers home. A young navy man of board, Lieutenant Dave Thatcher, and Dr. Haines slowly begin to piece together the nature of what is killing them, as more people, including the pilot, become sick and die. Pressure mounts, and some of the passengers are suspicious of Thatcher's knowledge of viruses and their effects. Will the plane make it back in time? Will it be allowed to land, and the passengers left alive allowed to disembark?