Mathematical genius Dr. Meg Brightwood has just completed her life's work-a proof of a problem so impenetrable it's nicknamed the Impossible Theorem. Reclusive and burdened by anxiety, Meg has long since been dismissed by academia. Now everyone wants to get their hands on what she alone possesses-especially her own mathematician father. Having grown up a prodigy in a field plagued by sexism and plagiarism, Meg opts for a public presentation so there will be no doubt of her authorship. But a panic attack obliterates her plans. In defeat, she goes home and locks away the one and only manuscript of her proof. Then chance sends her the unlikeliest of allies: Isaac Wells-carpenter, high school dropout, in trouble with the law. And the one love of Meg's life. Fifteen years ago, they did little more than hold hands. Now, they find a tenuous space where they can love and be loved for who they are-not who the world expects them to be. But when Meg goes to retrieve the Impossible Theorem, she finds it missing. Her fight for the achievement of the century will test the limits of her brilliance and the endurance of two vulnerable hearts.