Will George R.R. Martin ever finish the “A Song of Ice and Fire” series? There’ve been a lot of jokes about the 66-year-old writer’s slow progress, but the author behind HBO’s “Game of Thrones” appears to be moving along on the highly anticipated sixth book. Unfortunately, Martin had to make a big sacrifice in order to focus on the next installment. He revealed in a blog post Monday that he’ll be skipping a couple of upcoming events – including San Diego’s Comic-Con.

 Martin broke the news yesterday that he was limiting his appearances due to “time.” Besides San Diego Comic-Con, his announcement also affected the World Fantasy Convention in Saratoga, New York.

“I have too much to do,” he wrote. “Too many things on my plate. Son of Kong foremost amongst them.”

For those unaware, “Son of Kong” is Martin’s nickname for Book 6 in the “A Song of Fire and Ice” saga, “The Winds of Winter.” His fifth book, “A Dance of Dragons,” was released in 2011, and no date for “The Winds of Winter” has been revealed yet.

This isn’t the first time the author was forced to cut back because of the upcoming book. In July Martin revealed to Entertainment Weekly he'd be taking a break from “Game of Thrones” to work on the sixth novel. Martin wrote episodes for the first four seasons, but decided to skip Season 5 of the HBO show to work on the book.

But why the rush? Martin actually has two more installments to write to complete the saga. Besides “The Winds of Winter,” he also must write “A Dream of Spring.” Of course die-hard fans are looking forward to seeing how the series ends, but another big concern is “Game of Thrones.” The show is moving into its fifth season in April and is already almost caught up to “A Dance of Dragons.” Some characters have even been excluded from the upcoming drama because they show’s writers reached the end of the content available for them in the books.

It’s not clear when Martin plans on completing Book 6, but he did end his blog post with a major tease: “Should I complete and deliver WINDS OF WINTER before these cons roll around, I reserve the right to change my mind.”