The Puppet Masters

A UFO is reported over rural Iowa, triggering a top-secret inquiry. Andrew Nivens, who runs a CIA unit dedicated to extraterrestrials, dispatches two agents to the crash site. The goal is to determine if the sighting involves alien activity and what happened to the initial team.

The two agents vanish soon after their arrival, prompting Andrew to go in person with his son Sam, along with Jarvis and Dr. Mary Sefton. They press on the site to uncover the truth behind the disappearance. The emphasis is on a firsthand assessment of the alien threat.

At the site, the crash is revealed to be staged as a phony tourist attraction, suggesting a cover story. They encounter locals who seem emotionally flat, giving the team a chilling sense of unease. The absence of normal human responses hints at alien influence.

Mary tests the locals' humanity by attempting to seduce a local TV station manager; the manager remains unmoved. The lack of reaction reinforces the theory that something is controlling everyone's behavior. The moment underscores the crew's suspicion of an alien presence.

Sam tries to cuff the manager, triggering a brutal fight that ends with the manager dead. The team discovers an alien slug attached to the manager's back and captures it, then races to escape as infected townspeople block their path. They retreat to their plane to regroup.

The slugs begin to spread through the town, and during a staff meeting Sam notices that Jarvis has stopped chain-smoking, hinting at infection. They move to restrain him, but he appears unconscious and no longer hosts an alien. The growing threat becomes undeniable.

Andrew orders everyone to remove their shirts to reveal hidden parasites, but his secretary refuses and tries to flee. A brutal chase ends with the secretary dead in the office kitchen, while Sam and Alex realize the alien has escaped into the building. The team braces for a broader infection.

Sam is revealed to be infected, signaling a turning point in the crisis. Jarvis, overwhelmed by withdrawal from the parasite removal, commits suicide. The team must confront a now biochemically connected alien hive.

The infected Sam teams with Greenberg to release crates of parasites. The aliens communicate telepathically by touching tentacles and demonstrate healing abilities, revealing a terrifying collective intelligence.

The team heads to a convention center where a presidential meeting is planned and the aliens target the president's Secret Service detail. A tactical team of uninfected agents intervenes, preventing the infection from reaching the president. Sam is captured by his own father during the chaos.

At the agency, the infected Sam is interrogated. The team learns that the aliens fully control their hosts, including killing and resurrecting them. Electric shocks briefly disrupt the aliens’ control, harming the host in the process.

The aliens plan a wider spread; Sam and Alex parachute into Des Moines, which is fully infected. Sam enters the hive using a transmitter to block the aliens’ communications. Inside, Alex fights to help Sam escape, but is killed when Mary shoots him to prevent reinfection.

Back at base, the team discovers that applying encephalitis can destroy the parasites, triggering a biological countermeasure. During debris-related injuries, Andrew becomes infected. In a brutal helicopter chase, Sam shoots his father to force the alien from the body, which is killed by the helicopter's tail rotor.

With the last alien defeated, Andrew is treated and acknowledges Sam's love for him. Mary and Sam admit they know everything about each other, but they also accept that they have a lifetime to learn more, suggesting a hopeful future together free of parasite control.