Johnny and Bruce come back from an antique-hunting expedition and is greeted by a surprise party put together by his old science club students. They're interrupted by one of the students, Alex Conners, who challenges him to prove his psychic abilities by identifying the Indian head nickel he stole from Johnny 10 years ago. Johnny figures it out without touching him, but when he hugs him he gets a vision of Conners in Washington D.C. at the Lincoln Memorial disintegrating in flames just before a nuclear explosion sweeps across the capital.
Conners reveals he's working on plastics and Johnny wrangles an invitation and meets with Conners the next day, and they discuss a polymer that Conners is having problems with. Meanwhile Rev. Purdy meets with Stillson, who tries to pressure the Reverend into donating more money and leaves with a cryptic warning. Johnny works with Conners to come up with a working polymer sample and Alex mentions how he doesn't want to use his science for the military. After their work fails, Johnny touches a sample of the polymer Alex has been working with; he gets a vision of Conners at a meeting with Stillson before the nuclear explosion occurs again. Johnny believes Alex is the "flashpoint" but can't figure out why. The next day they discuss the matter and Johnny figures that the failed experiment has lead to a creation of a bendable plastic with high levels of radiation shielding. Conners boss comes in and when they shake hands he gets a vision of her meeting with Stillson and discussing financing of his campaign and how they'll be working together.
Johnny resolves to sabotage Conners' work against Bruce's advice and subtly alters the formula. Reverend Purdy is making a broadcast when their signal gets cut off and his mysterious benefactor Malcolm Janus shows up to advise him to increase his donations to Stillson. Stillson and Janus talk and Stillson tells Janus to check out Johnny at the laboratory. Conners' experiments fail while Johnny talks to Sara about the fact she and Walt are planning to have another child. Conners figures out that Johnny is doing something and he gets a vision of Stillson and Peck visiting Conners as he succeeds. Johnny describes the encounter and tries to warn Alex about Stillson, who has him kicked out.
Later Johnny's prediction comes true and Stillson tells Janus to make sure Stillson and Conners don't get together again outside of the lab. Johnny and Bruce go to the lab and Johnny gets a vision of Conners on his bike and two goons coming after him. Conners arrive seconds later and Johnny tells him to meet him later, while Bruce runs interference. They meet later in secret and Johnny reveals his vision of the apocalypse and Conners resolves to destroy the sample and end the project. When Johnny touches the sample, he sees that the President is at the "inauguration" of the plastic sample . . . and Stillson is the President of the U.S.
Conners decides he needs to trash the hard drive and he's the only one who can do it. Stillson is meeting with a Senator Ellis and is introduced to his daughter Miranda. The two seem to hit it off and afterward Johnny sneaks in to meet with Stillson. He tells Stillson to let Conners walk away if in return he stays away from Stillson. Stillson agrees but after he leaves Stillson orders Conners brought in. Johnny finds an unconscious Bruce and gets a vision of Conners being grabbed after his family is threatened. Johnny goes to the lab and gets a vision of Conners erasing the formulas and wiping the hard drive, then setting a fire. When security shows up, Conners seals himself in the lab and is caught in the blast when the laboratory. Johnny realizes that Conners was killed right now, not in the future. Johnny and Bruce get in just in time to see Conners killed in the blast. Johnny offers his condolences to Conners' parents and leaves the Indian head nickel on Alex's coffin. Bruce advises that Johnny get some rest to figure things out. Stillson is working with Trey, Conners' lab partner, and turns over all the data he has in return for a big cash payment.