Only when Darwin retreats to his study and begins to discuss his day with his daughter Annie, a precocious and inquisitive ten year old, do we see him come to life. But when Emma comes in to find Darwin alone, we realise he has not been talking to a living being. Not an apparition, but the vibrant spirit of Darwin’s favourite child who died several years earlier.
The story moves back and forth through Annie’s short life and the years following her death. Not only does a portrait of a deeply connected father-daughter relationship emerge, so does Darwin’s magnificent theory. Annie's death sharpens Darwin’s conviction that natural laws have nothing to do with divine intervention. To his contemporaries, this is a very dangerous and threatening idea. In a box in Darwin’s study, we discover the manuscript of ‘On the Origin of Species.’
Darwin makes a poignant pilgrimage to the hotel in Malvern where Annie died whilst receiving treatment. The journey marks a change in him, and he is finally able to share his grief with Emma. The couple reconnect at last. Emma is both shocked by her husband’s views and in love all over again with his passion and intellect. Darwin decides that Emma must make the decision about publishing his work. After reading the manuscript, she quietly returns it to him addressed to a publisher in London. For both of the Darwins, love takes priority over belief.
Darwin walks down the lane, holding the package. The postman arrives. Darwin falters, almost letting him go empty-handed. The postman rides away unaware of the time-bomb he’s carrying out into the world. As Darwin walks home, a little girl skips happily alongside him.