Phase IV

Phase IV

Year: 1974

Runtime: 84 min

Language: English

Director: Saul Bass

Sci-FiThrillerHorror

While researching the death of a friend, a journalism student's investigation takes a disturbing turn, blurring the lines between reality and paranoia. As he delves deeper, Dean Cain finds himself increasingly isolated and unsure of who he can trust. The pursuit of the truth becomes a dangerous game, with the police and a shadowy killer closing in. He must unravel the mystery before it consumes him.

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Phase IV (1974) – Full Plot Summary & Ending Explained

Read the complete plot breakdown of Phase IV (1974), including all key story events, major twists, and the ending explained in detail. Discover what really happened—and what it all means.

In this science-meets-surprise thriller, a spectacular and mysterious cosmic event triggers rapid evolution among ants of different species, forging a cross-species hive mind that drives them toward seven geometrically perfect towers rising from the Arizona desert. As the ants begin to display an unsettling unity and intelligence, the human population largely flees, save for one family that clings to the edge of the mystery.

Two scientists, James R. Lesko and Ernest D. Hubbs, set up a computerized lab inside a sealed dome in a zone of intense ant activity, hoping to study and perhaps outwit this extraordinary insect civilization. Inside their high-tech enclave, they discover an enemy that is not only agile but immune to human chemical weapons, and soon the ants infiltrate the lab, infiltrating the computers and threatening to short-circuit the entire operation.

As the ants press their advantage, a young woman named Kendra Eldridge, who has taken refuge with the scientists, decodes an enigmatic ant message and becomes convinced that her own actions may have provoked the ants’ aggression. Her concern grows into a desperate resolve to protect the researchers, and she ultimately leaves the lab in a bid to save them—an act that appears to be a selfless sacrifice.

Meanwhile, the two scientists diverge on how to respond. Lesko believes there might be a way to communicate with the ant state through mathematical messages, a hopeful attempt to bridge the two species’ worlds. Hubbs, driven by fear and the sting of venom, clings to a grimmer plan: to wipe out what he believes is the ants’ central hive. The situation escalates when Hubbs, delirious from an ant sting, tumbles into a deep pit that the ants fill with earth, rendering him unable to continue the fight.

Without delay, Lesko embraces Hubbs’s path, determined to reach the hive and confront the heart of the colony using a canister of insecticide. He descends into the hive, hunting for the queen, only to stumble upon a stirring revelation: Kendra is there beneath the sands, and the moment of reunion makes him realize a far more profound truth. Far from seeking human extinction, the ants seem intent on integrating humanity into their world—an astonishing and unsettling reorientation of coexistence rather than conquest.

As the narrative unfolds, the climactic realization settles in: the ants’ plan is not to destroy man, but to adapt him into their ecosystem. The film closes with a haunting voice-over from Lesko, admitting that they do not yet know what plans the ants have, but they are waiting for instructions—and the future of humanity appears to be intertwined, not simply opposed, to the newly unified insect colony.

Last Updated: October 04, 2025 at 10:30

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Phase IV Timeline

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Phase IV Timeline

Characters, Settings & Themes in Phase IV

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Characters, Settings & Themes in Phase IV

More About Phase IV

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