"You Win or You Die"
Peter Dinklage stars as the cunning Tyrion in the second season of Game of Thrones, based on the novel Clash of Kings

As the new trailer for Game of Thrones' second season has fans in a frenzy, readers of the novels that inspired the show are concerned that the author may never finish the series.

George R. R. Martin's epic fantasy saga, A Song of Ice and Fire, has a hugely devoted fan base addicted to the five books released of a planned seven.

The release of A Dance With Dragons in July and the success of the big budget television adaptation has seen fans given a new concern - will they ever see the series finished?

Author George R. R. Martin does not lack ambition and has promised to tie up the series within seven books, with two more, provisionally titled The Winds of Winter and A Dream of Spring, still to come.

However increasing delays between each doorstop sized book means are fans concerned that the 63-year-old author might not manage to complete his vision.

The first book of the series, A Game of Thrones, was released in August 1996, with sequel A Clash of Kings coming two years later in 1998. Fans had another two-year wait before A Storm of Swords.

Fans then had to suffer a wait of more than five years for fourth book A Feast For Crows, which was released in October 2005. Then followed the longest wait yet, as A Dance With Dragons was not released until July 2011.

An ageing author, increasing delays between each book and the prospect of a decade before the series is finished has led to fans besieging Martin with calls to finish the books, even criticising him for taking a holiday.

The level of pressure put on the author led him to make an outburst on his blog. He said: "Some of you don't want me attending conventions, teaching workshops, touring and doing promo...After all, as some of you like to point out in your emails, I am 60 years old and fat and you don't want me to 'pull a Robert Jordan [who died before finishing a series of books ]' on you and deny you your book. Ok I've got the message.

"You don't want me doing anything except A Song of Ice and Fire. Ever. Well maybe it's ok if I take a leak once in a while?"

oncerns over the author's longevity aside, keen fans can hope that the success of their favourite characters' television incarnations will see the saga come to a satisfying conclusion, whether on a page or screen.