Rosamund Pike plays a nurse named Miranda, suffering from some sort of OCD behavior and probably more than a bit of germaphobia, something which does get on the nerves of coworkers and people milling about in public alike. A blind date setup ends up with her being sexually assaulted and beaten in her own home by a fixated man she doesn't really know named William (played by Joaquin Phoenix doppelganger, Shiloh Fernandez). William's off to prison as Miranda mends her wounds, only to later start to write to him (something he rejects for a while, leading to the reason for the movie's title), and even start weekly visits to see how he's doing in prison.