Official submission of Spain to the Oscars 2014 best foreign language film category.
Director Gracia Querejeta gave parts of the screenplay to her teenage son and his friends to help get the colloquial language and expressions as accurate as possible.
It was Maribel Verdú's idea to shoot her confessional monologue on the hospital in a sequence-shot.
The role of Maribel Verdú was written for her.