Game of Thrones fans are well aware of the fact that George R.R. Martin — author of the books behind the HBO show — just can't finish the last two novels in the series.

Ahead of Game of Thrones' return to the small screen on Sunday night, Saturday Night Live explained why it's taking Martin so long to wrap things up. Check out the clip, above, starting at the 1:40 mark.

"I'm burnt out — it's just so vast," Martin (played by cast member Bobby Moynihan) said on SNL's "Weekend Update" segment. "Do you have any idea how hard it is to name one thousand characters? ... The same goes for the kingdom names. A lot of the next book just takes place in Denver."

Moynihan as Martin confessed he's been getting inspiration from watching old sitcoms such as Friends, and has been sidetracked by pornographic fan fiction. But at least he didn't leave the "Weekend Update" desk without hinting at what's to come:

"I will tell you this: It's 3,000 pages long, everyone you have grown to love dies ... and something shocking is coming ... It's winter; winter is coming," he said.

Bonus: Stunning 'Game of Thrones' Puzzle in All Its 3D Glory

'Game of Thrones' 3D Puzzle

1. Iron Throne

   3D miniature pieces, such as the iron throne, are inserted into the puzzle.

2. Puzzle Size

   The 3D puzzle, which measures in at 30 by 18 by 2 inches, costs $59.99 at various retailers.

3. Winterfell

   A look at Winterfell, the Stark family's castle in the north.

4. Landmarks

   Other landmarks include Dragonstone, Casterly Rock and Pyke castle.

5. First Layer

   The first layer consists of a 1000-plus-piece puzzle, but there are more than 1,400 pieces in total.

6. Flags and Sigils

   The puzzle also comes with 45 flags that indicate landmarks, as well as 10 sigils to identify the houses. There's also five markers for each of the major battles.

7. King's Landing

   King's Landing is the capital of the Seven Kingdoms, and is located on the east coast.

8. The Wall

   This 300-mile-long wall is made out of ice. It borders the north, and keeps out the wildlings and the White Walkers.

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