Abandoning their dying planet, a species of gelatinous creatures travels to Earth and land in San Francisco. They take the form of plants with pink flowers that reproduce with pods. Elizabeth Driscoll (Brooke Adams), a scientist with the San Francisco Health Department, brings one home. The next day, she finds her boyfriend Geoffrey Howell (Art Hindle) acting strangely cold and distant.
Her colleague Matthew Bennell (Donald Sutherland) advises her to speak to his psychiatrist friend David Kibner (Leonard Nimoy), who is having a book-signing. As they drive to the bookstore, they are accosted by a man (Kevin McCarthy) screaming, “They’re coming! You’ll be next!” He is then hit by a car. At the bookstore, Elizabeth asks David for help with Geoffrey. He is as helpful as every shrink in a horror movie, suggesting she is using Geoffrey’s supposed change to end their relationship. Matthew reports the man in the street to the police, but they seem not to believe him.
Other people begin to complain that their loved ones are acting strangely. Matthew’s friend Jack Bellicec (Jeff Goldblum) finds a body resembling him, covered in fibers, in his wife Nancy’s (Veronica Cartwright) mud baths. Becoming worried, Matthew goes to warn Elizabeth, but finds her in a deep sleep and a half-completed duplicate of her in the next room. He takes Elizabeth home with him and returns with the police, but the duplicate is gone.
The next night, in an amazingly gross scene, Matthew and his friends are almost duplicated in their sleep by four pods in his garden. The pods grow and open up and a swiftly grown duplicate is born. Then the original dies and disintegrates. Matthew calls the police but finds the whole department infiltrated. They are tracking him through the phone-lines. He destroys his duplicate before it can be completed and escapes, followed by aliens emitting a shrill scream when they spot an original human. Jack and Nancy create a distraction, allowing Matthew and Elizabeth to escape. They hide out in the Health Department, taking speed to stay awake, but their friends, duplicated, show up. They kill Jack’s duplicate, lock David’s in a refrigerated room, and escape again.
Matthew and Elizabeth reunite with Nancy, who has learned to hide her emotions and escape detection. They try the same, but Elizabeth sees a dog with a human head and screams. They lose Nancy in the chaos and use a truck to reach Pier 70, where more pods are being shipped all over the world. Matthew returns to Elizabeth, but she disintegrates in her sleep. He is pursued by her shrieking duplicate. He burns down the warehouse, destroying hundreds of pods. Walking like an alien, showing no emotion, he hides for a time. Nancy approaches him and attempts a hushed conversation, but he points at her and shrieks.
The film was directed by Phillip Kaufmann, a big fan of the 1956 version, together with cinematographer Michael Chapman, trying to capture the film-noir feeling of the original. The man trying to warn drivers of impending doom in the beginning was Kevin McCarthy, star of the original film, basically reprising its final scene. The director of the 1956 film was in the remake as well. The shock ending was a surprise to all the actors but one, capturing their astonishment. That cast was pretty impressive—Donald Sutherland, Brooke Adams, Leonard Nimoy, Jeff Goldblum, Veronica Cartwright, even Robert Duval in a strange cameo.
The movie was released on the 40th Anniversary of the original, shortly after the Jonestown mass suicide. Most reviews were raves. It was nominated for a Hugo and several awards from the Academy of Science-Fiction, Fantasy, and Horror Films. Robert Duvall’s cameo as a crazy priest on a swing was done for free. While Kevin McCarthy was rehearsing, a naked homeless man told him, “The original was better.” Welcome to San Francisco. After the release, somebody scattered pods throughout Los Angeles. In a footrace challenge, Brooke Adams beat Donald Sutherland in a dress and high heels. There was no music after the chilling last scene.