Over two turbulent weeks in 1858, Charles Darwin (Henry Ian Cusick) faces crises both personal and professional: One of his children has diphtheria, another child has scarlet fever, and an unknown naturalist may scoop his not-yet-published theory of natural selection. Luckily, Darwin's loving wife, Emma (Frances O'Connor), is there to guide him through his darkest hour in this fascinating television biopic of the great scientist.