Harold Franklin "Harry" Benson, a computer scientist in his mid-thirties, is described as suffering from "psychomotor epilepsy"[4] following a car crash two years earlier.

The ramifications of the procedure are questioned by the NPS's staff psychiatrist, Janet Ross, and later by her former teacher, Manon, an emeritus professor.

Ellis admits that what they are doing is not a cure for Benson's personality disorder, but will simply stimulate the brain preventatively when a computer senses an oncoming seizure.

Benson must wear a dog tag with instructions to call University Hospital if he is injured, as his power pack may emit radiation.

Gerhard, one of the technicians administering the test, shows his findings to Ross, who discovers that the seizures are becoming more frequent.

She then finds out that Benson, using the wig and disguising himself as an orderly, has evaded the police officer assigned to guard him and escaped from the hospital.

Ross goes to Benson's house, where she finds two girls who say he has a gun and possesses blueprints for the basement of the hospital, where the computer mainframe is located.

Just before losing consciousness, Ross manages to turn on her microwave oven, the radiation of which affects the power pack in Benson's shoulder and forces him to flee.

Los Angeles Times called it "an entertaining and unsparing narrative, compressed and scientifically sound.

[10] Crichton's technological sci-fi premise became reality half a century later, in 2023, when a British boy had a neurostimulator fitted inside his skull, sending electrical signals deep into his brain to control seizures.