A young scientist from 2D space must solve mathematical mysteries to save a doomed space mission and discover the true shape of her universe. In a world of only two dimensions, length and width, the geometrical inhabitants of Flatland dismiss the idea of the third dimension. But when a scientist (Danny Pudi) discovers a mathematical anomaly, he turns to the only person who might listen - Hex (Kristen Bell), an outcast mathematician shunned for her ideas of the third dimension. An unexpected reunion with Spherius (Michael York), a 3D being, plunges the two Flatlanders into a journey across dimensions as they race to discover the true shape of their universe.