The film starts with a young woman named Becky (Greer Kent), shown to be trapped in the Cube. She enters another room, but unknown to her, the room has reversed gravity, as she is pulled up.
Max Cohen is the story's protagonist and unreliable narrator. Unemployed, and living in a dreary Chinatown apartment in New York City, Max is a number theorist who believes that everything in nature can be understood through numbers. He is capable of doing simple arithmetic calculations involving large numbers in his head, a skill that impresses Jenna, a small Chinese-American girl with a calculator who lives in his apartment building. Max also suffers from cluster headaches, as well as extreme paranoia, hallucinations, and social anxiety disorder. Other than Devi, a young woman living next door who sometimes speaks to him, Max's only social interaction is with Sol Robeson, his old mathematics mentor who is now an invalid.
Au commencement, un homme et une femme achèvent un pique-nique et entament une sieste au bord d'un lac à Chicago. La caméra qui les filme est placée à un mètre au-dessus d'eux. Elle reste centrée sur ce couple, mais va progressivement s'éloigner vers le haut, permettant au fur et à mesure d'avoir un champ de vision de plus en plus vaste sur ce qui entoure la scène initiale. La largeur du champ de vision et la hauteur du point de vue de la scène sont multipliées par 10 toutes les dix secondes, jusqu'à ce que l'on arrive aux limites observables de l'univers. Une fois « là », dans l'infiment grand, la caméra fait machine arrière, en accéléré, pour revenir sur la main de l'homme (toujours allongé sur l'herbe). La caméra pénètre alors la main de l'homme pour arriver cette fois à l'échelle du plus petit élément connu : le quark.
Donald Duck explique, grâce à plusieurs aventures dans le monde de l'animation, l'avantage des mathématiques dans le quotidien ainsi que quelques applications pratiques des mathématiques.
Chacko Master (Thilakan) is a high-school headmaster who is a president's medal winner in Mathematics. He is a very strict teacher and emphasizes memorization and discipline at the expense of analysis and creativity in school. He punishes his students ruthlessly and gives no special treatment to his son Thomas, who is also a student in his class. Chacko always assumes that his son is behind every mischief in class, and punishes him until the actual culprit gives himself in.
The film starts with a man, Ryjkin, trying to escape from the Cube. He enters a cube and is sprayed with liquid that he thinks is only water. However, when he rubs the back of his hand, a piece of flesh falls off. This continues all over his body, and he then melts on the floor and dies.
In 1993, Martin (Elijah Wood), a US student at the University of Oxford, wants Arthur Seldom (Hurt) as his thesis supervisor. He idolises Seldom and has learned all about him. He takes accommodation in Oxford at the house of Mrs. Eagleton (Anna Massey), an old friend of Seldom. Also in the house is her daughter, Beth (Julie Cox), who is her full-time caregiver — which she resents bitterly — and a musician by occupation.
The four mathematicians are gathered and meet with a top official of the United States Department of Defense. After some discussion, the group agrees that they must be wary with whom to trust and control their solution. The official offers them a reward of $10 million in exchange for their portion of the algorithm, swaying them by attempting to address their concerns. Only one of the four speaks out against the sale, and in doing so is forced to reveal a dark truth about his portion of the solution. Before they sign a license to the government, however, they wrestle with the ethical consequences of their discovery.
Emmy Coer is a computer scientist obsessed with Countess Ada Lovelace, author of the first computer algorithm, written for Charles Babbage's "Analytical Engine". She finds a way of communicating with people in the past by way of "undying information waves". In the film, Ada's ideas are portrayed as limited by discrimination against women in technology, science and mathematics in her time. Much of the story revolves around Coer's attempts to use genetic engineering to bring Countess Lovelace into the present.
Dr. Charles A. Forbin (Eric Braeden) is the chief designer of a secret government project that has built "Colossus", an advanced supercomputer to control the United States and Allied nuclear weapons systems. Being encased within a mountain, it is impervious to attack, powered by its own nuclear reactor. When Colossus is activated, the President of the United States (Gordon Pinsent) announces its existence, proudly proclaiming it a perfect defense system.
Nancy Nestor (Wendie Malick) is the perfect wife and mother now at her wits' end when her teenage genius son Hal (Justin Long) looks himself in the bathroom for months to work on a mathematical equation which involves studying of Lacy Baldwin (Danica McKellar), a cheerleader next door, as she bounces up and down on a trampoline. Nancy's husband Dwight (Stephen Root) is too wrapped up in his own petty concerns to help her. When a burglary brings the police to inspect the crime scene, they find Hal locked in the bathroom and suspect he is being held against his will and call Social Services.
Lille, 1996. Sabine, issue d'une famille ayant des problèmes financiers, est une adolescente de 15 ans, surdouée en maths, dont le caractère est déjà bien affirmé. Déterminée, paraissant sûre d'elle et ayant déjà sa propre vision du monde, beaucoup liée aux mathématiques, elle rencontre un homme de quarante ans, immigré de Tchécoslovaquie, avec qui elle noue peu à peu des liens passionnels.