A pregnant Captain Kirk gives birth on the Enterprise, Harry Potter and his rival Draco Malfoy fall in love and you take a starring role in your favourite book, film or TV show. Seems unlikely? With fanfiction any of this - and more - becomes possible.

Fanfiction is a global phenomenon with amateur writers creating new stories in the existing fictional worlds of their most loved films, TV shows and books. For many it is an obsession – but why do they do it? And, how do the writers whose works are taken on by the fanfiction community feel about it?

It is not for the money; fanfiction is a non-commercial pursuit, although some writers do make the transition from amateur to published author. The most famous example of this is E.L. James, whose blockbuster book 50 Shades of Grey, started out as fanfiction based on the Vampire inspired Twilight series. Chilean author Francisca Solar tells us how her own Harry Potter fanfiction landed her a book contract.

But turning pro is not the goal for most ‘fanfic’ writers; it is the freedom to play with their most loved characters in a uniquely creative world, with very few limits.

(Photo: A black and white picture of Captain Kirk and Mr Spock credit: Robyn Beck/AFP/Getty Images)