Laurel Healy, an aspiring documentary filmmaker, reluctantly takes a job working for her brother, Democratic Senator Luke Healy, in Washington, D.C., to fund her latest project. Upon arrival, Laurel quickly realizes that the nation's capital is behaving strangely, characterized by bizarre political deadlocks and sudden, radical shifts in politicians' personalities. She teams up with Gareth Ritter, a sharp chief of staff for a conservative Republican senator, and Dr. Gustav Triplett, an eccentric brain surgeon and
conspiracy theorist, to uncover the truth behind the madness.The trio discovers an extraterrestrial threat: microscopic alien bugs have arrived on a meteor and are burrowing into the brains of Washington elites, politicians, and staffers. Once inside, these parasites consume half of the host’s brain, drastically altering their behavior, making them fanatical partisans, and forcing them to act as a hive mind bent on escalating political polarization to blind the public to the invasion. The infected exhibit gross physical symptoms, including exploding heads when exposed to specific sounds, and they communicate via The Cars’ song "You Might Think."As the infestation spreads, Laurel, Gareth, and Gustav race against time to find a way to eliminate the bugs without killing their human hosts. They discover that the aliens are breeding a queen to take over the entire country. Simultaneously, Laurel’s personal life becomes complicated as she develops a slow-burn romantic tension with Gareth, who eventually becomes infected before being cured, and deals with her family's entanglement in the political circus. Luke Healy finds himself at the center of the political storm, initially targeted by the bugs because of his moderate tendencies, forcing him to navigate a treacherous landscape where allies are constantly being replaced by pod-people.The conspiracy reaches its apex during a massive government shutdown. The alien queen is nearing maturity, and the hive mind orchestrates a final push to ratify a
constitutional convention that would effectively hand control of the United States over to the extraterrestrials. Laurel and her team infiltrate the secure facility housing the queen. In a chaotic climax involving loud music, which disrupts the hive mind, they manage to destroy the alien queen and neutralize the remaining parasites, saving Washington from total subjugation. With the capital miraculously returning to its normal, albeit still dysfunctional, political state, Laurel finally achieves her dream of finishing her documentary, while she and Gareth part ways on bittersweet terms, forever bonded by their shared, surreal ordeal to save humanity from the inside out.