Katherine is struggling to come to terms with the death of her father, an eminent mathematician, whose genius coexisted with madness. One of her father's former students, Hal, helps her to overcome grief, long hidden fears and mental depression. He delves into the scientists' notebooks hoping to find another proof of his greatness. While Katherine is horrified thinking about what price she would have to pay for the gift she inherited her sister comes, who decided to help settle their father's affairs.