John Nash first arrives as a new graduate student at Princeton University. There he meets his roommate Charles, a literature student, who soon becomes his best friend. He also meets a group of other promising math and science graduate students.
John sometimes goes out to a bar with his fellow students to try to meet women, but is always unsuccessful. However, the experience is what ultimately inspires his work in the concept of governing dynamics, a theory in mathematical economics. After the conclusion of John's studies as a student at Princeton, he accepts a teaching offer at a prestigious institution, along with his friends Sol and Bender. It is while at this post that he meets Alicia, a student with whom he falls in love and eventually marries. While at Princeton, Nash runs into his former roommate Charles and meets Charles's young niece Marcee.
John Nash receives an invitation to the Pentagon to crack a complex encryption of enemy codes. He is able to decipher these codes mentally, impressing a certain mysterious William Parcher. This man later encourages John Nash to work for the government by looking for patterns in magazines and newspapers for a Soviet Plot. Involvement with Parcher came with chase scenes and gunfire, Nash eventually became paranoid and began behaving aggressively.
In an attempt to help out a friend, Sol followed Nash during one of his late night top secret drop offs. Here Nash was seen placing enveloped documents in a mailbox at an abandoned establishment. Then one day during a lecture, Nash was caught trying to flee. He was sedated and sent to a psychiatric facility where he was interrogated.
Alicia Nash, desperate to help her husband, visits the abandoned building only to find the never-opened "top secret" documents that Nash dropped there. She confronted her husband with this evidence, which at first he tried to deny true. Eventually he realized that William Parcher and the top secret missions were in fact all a delusion.
He had to go through a painful series of insulin shock therapy sessions. Afterwards Nash is released on the condition that he agrees to take antipsychotic medication. These drugs however, had side effects that affected his relationship with his wife. Frustrated, He secretly stops taking medication, which triggered a relapse. While bathing their baby, Nash becomes distracted and wanders off. Fortunately his wife manages to save their child from drowning. When she confronts Nash, he claims that his friend Charles was watching their son. Alicia was alarmed desperately trying to contact professional help. Charles, Marcee, and Parcher all appear to John and urge him to kill his wife rather than allow her to lock him up again. Just when Alicia was about to leave, Nash finally realizes that these people are not real when he observes that Marcee never gets old. Only then does he accept that all three of these people are, in fact, part of his psychosis.
From then on, Nash tries to live with these delusions by ignoring them. In his struggle to ignore these hallucinations, he approaches his old friend and rival Martin Hansen, now head of Princeton University. He is accepted to teach again. He is honored by his fellow professors for his achievement in mathematics. He won the Nobel Memorial Prize in Economics for his revolutionary work on game theory. He got up and gave out his speech.
“I've always believed in numbers and the equations and logics that lead to reason.
But after a lifetime of such pursuits, I ask,
"What truly is logic?"
"Who decides reason?"
My quest has taken me through the physical, the metaphysical, the delusional -- and back.
And I have made the most important discovery of my career, the most important discovery of my life: It is only in the mysterious equations of love that any logic or reasons can be found.
I'm only here tonight because of you Alicia
You are the reason I am.