Extinct takes place 400 years after the extinction of the human race and follows a small group of humans who are revived by an alien civilization. Over the course of the season, the series carries the colony of revived humans through struggles with the aliens who extinguished humankind centuries before, while trying to understand and get along with the mysterious aliens who revived them.
Four hundred years after the extinction of the human race, a seemingly benevolent alien species regenerates three humans. Confused about their new life, the reborn humans agree to help each other, only to discover new dangers on Earth that threaten to annihilate the human race all over again.
Abram discovers an alien structure and attempts to learn more about it, while Ezra seeks to recover an object that may bring back more humans. Feena's troubled past is revealed when a Skin Rider attempts to reach the settlement.
The obelisk agrees to bring back more humans, so Feena travels to the lake to escort the new Reborns back to the settlement. A mysterious girl appears in the forest, and Abram discovers a secret about the first settlers.
Ezra and Lynn are captured by the previous settlers and hope to find Kylie among them. Silas attempts to strengthen the Skin Rider parasite, and Feena and Abram search for a buried drone they believe contains vital information.