After the space shuttle Patriot crashes on Earth, a fungus-like alien lifeform is discovered on the remaining parts scattered over U.S. territory. Once people come into contact with the organism, they are controlled by it when they enter REM sleep. One of the first people infected is Tucker Kaufman, a CDC director investigating the crash.
Tucker’s ex-wife, psychiatrist Carol Bennell, begins to feel something is amiss when people seem to have “changed”. Her patient Wendy Lenk describes how her husband “is not her husband”, and one of her son’s friends acts detached and emotionless. At a neighborhood Halloween party, Carol’s son Oliver finds a “skin” on a partier which is initially believed to be costume makeup. Carol speculates that the skin may be an organism connected to reports of a fast-spreading flu. Carol takes the organism to her doctor friend Ben Driscoll to have it checked. Carol attends a friendly dinner meeting between Russian diplomat Yorish and Czechoslovakian diplomat Belicec (along with female companion Luddie) and discusses her postmodern feminism views over caviar and champagne. Meanwhile, Tucker uses the CDC to spread the disease further, disguising the spores as flu vaccine.