This drama is based on David Auburn's pulitzer prize-winning play. Catherine (Gwyneth Paltrow) is the daughter of an intelligent, but mentally ill mathematician professor (Anthony Hopkins). Catherine had to put her own ambitions in mathematics and her social life to the side, so she could take care of her father until his death. After the funeral, her dominant sister (Hope Davis) stay so she could keep an eye on her and also finish their father's business. At the same time, one of his old students (Jake Gyllenhaal) appears and asks to go through the professor’s notebooks in the hope of finding valuable information. Catherine must therefore take a lot of decisions, but the big question is; how much of her father's intelligence and madness did she inherit?