What does that 'Game of Thrones' twist mean for the George R. R. Martin books?

The newest episode of HBO's smash hit "Game of Thrones" included an answer to one of the show's biggest cliffhangers.

(Spoilers for the May 1 episode of the program follow…) 

At the end of the newest "Thrones" episode, Jon Snow (Kit Harington), the commander of the military force the Night's Watch, who appeared to be killed by his men at the end of the previous season's finale, seems to have been revived by the Red Priestess Melisandre (Carice van Houten). 

The show's audience has previously seen people who are apparently dead be revived by those who follow Melisandre's religion, that of the Lord of Light.

The last book released so far in the "Song of Ice and Fire" series by George R. R. Martin, on which "Thrones" is based, ended Jon's storyline with the character being killed by members of the Night's Watch. 

So far, fans seem to be mainly excited about the new development. "It's joyous news for Jon fans worldwide," Alan Eyerly of the Los Angeles Times wrote.

But the revelation does represent a shift for fans of both the TV show and Mr. Martin's books. Last season, the storylines of many "Thrones" characters were brought to the point seen in Martin’s newest book, "A Dance with Dragons," so for TV and book readers, much of what is happening this season is new.

The sixth season premiere also contained a surprise, the revelation that Melisandre herself is seemingly much older than she appears. But Jon Snow's fate is one that has been debated by fans since 2011, when "Dragon" was published.

Are events playing out differently in the show, though? That is, will the TV show not reveal events of the books to fans? "Thrones" co-creators David Benioff and Dan Weiss told Entertainment Weekly that fans of the book series don't need to worry about plot points being given away by the show. 

"People are talking about whether the books are going to be spoiled – and it's really not true," Mr. Benioff said. "So much of what we're doing diverges from the books at this point. And while there are certain key elements that will be the same, we're not going to talk so much about that – and I don't think George is either. People are going to be very surprised when they read the books after the show. They're quite divergent in so many respects for the remainder of the show." 

Mr. Weiss added, "There's this amazing world George has created and now there are two different versions."

Of course, now that Jon's story has been revealed on the show, some writers are pointing out that the books have been full of what seeming indications that Jon is alive, too, with Vox writer Andrew Prokop writing, "The early episodes of the new season are set to resolve this dangling thread [of Jon Snow's story] for both groups of fans – one of the biggest cases in which the show will be 'spoiling' future books." 

However, in terms of the show as a whole, many characters and plot developments have already differed from Martin's books, as Charlie Jane Anders of io9 wrote prior to the latest episode, so the program won't actually be "spoiling" secrets for readers.

"Whenever [Martin's next "Thrones" book] "Winds of Winter" comes out, it'll still be a huge big deal, and it will still be full of surprises," Ms. Anders writes.

"A lot of the subplots in Martin's books will never even get to television at this point," she notes, adding, "You have to assume that these added complications, which are probably a huge part of why Martin is having so much more trouble bringing all the threads together in the final books, will end up having a big impact. Meanwhile, the TV show has also taken huge liberties."