Naturally, Martin has mixed feelings about that.

Its been an incredible ride, the author tells EW.

And almost all of it has been great.

USA. 2014. Author George RR Martin.

©Christopher Anderson / Magnum

Obviously, I wished I finished these books sooner so the show hadnt gotten ahead of me.

I never anticipated that.

Theres also a planned seventh novel,A Dream of Spring.

Since then, its been unclear how closely the shows story line hews to Martins future books.

Martin initially contributed one script per season to the series, then halted his contributions.

After season 4, George made a conscious decision to devote himself to the books, Weiss says.

And Jon Snows parentage is almost certainly the same as his plan.

But the rest of Martins narrative is a mystery, which is how the showrunners hope to keep it.

But more surprising is that Martin is likewise somewhat in the dark on the shows ending.

I know some of the things.

But theres a lot of minor-character [arcs] theyll be coming up with on their own.

And, of course, they passed me several years ago.

There may be important discrepancies.

Benioff and Weiss invited Martin to film a cameo in Northern Ireland for the final episodes.

He had previously filmed an appearance in the shows original pilot, playing a guest in Danys wedding.

But subsequent reshoots resulted in his footage being scrapped.

I was tempted to do [the final season cameo], Martin says.

Its the end for a lot of people, Martin says.

Its not the end for me.

Im still deeply in it.

I better live a long time because I have a lot of work left to do.

Game of Thronesreturns April 14.

EW.com will continue to have daily coverage through the end of the season.