Hannah, the protagonist, is a young woman who was given up for adoption as a baby and has been living in California. She has always been curious about her roots and when she discovers a clue that her birth mother may have been from Gatlin, she decides to go there to investigate.
On the way, she picks up a hitchhiker who introduces himself as "Zachariah" and seems to know more about Hannah's past than he should. He ominously quotes passages from the Book of Revelation, predicting a dark fate for Hannah.
Once in Gatlin, Hannah discovers that something strange is happening in the town. The children are acting eerily obedient and the adults seem to be hiding something from her. She eventually finds her way to the hospital where Isaac, the former leader of the Children of the Corn cult, has been in a coma for years.
Isaac wakes up and immediately recognizes Hannah as the "final sacrifice" that the cult needs to fulfill their prophecy. The town's residents are all devoted followers of Isaac, including his right-hand man, Micah, who is also Hannah's biological father.
As Hannah tries to uncover the truth about her mother and why she was given up for adoption, she becomes entangled in the cult's plans to bring about the end of the world. They believe that sacrificing her will bring about a new age of purity and righteousness.
With the help of Zachariah and a sympathetic doctor, Hannah must find a way to escape the cult's clutches and stop them from carrying out their deadly plan. In the end, she discovers shocking truths about her past and her connection to the Children of the Corn.