Author George R.R. Martin has bad news for his hordes of fans. "The Winds of Winter is not finished ... The book's not done. Nor is it likely to be finished tomorrow, or next week," the author wrote on his blog on Saturday.

The sixth installment of A Song of Ice and Fire — the novel series on which HBO's hit Game of Thrones is based — was originally scheduled to be completed before the end of 2015. But the author has now blown two deadlines given to him by his publisher, and he has now confirmed that The Winds of Winter won't arrive before season six of Game of Thrones this April. And for those who've read all of the novels, they'll be in the unusual position of being spoiled by an adaptation of a book that hasn't been completed yet.

"I won't make excuses. There are no excuses."

In a heartfelt and lengthy blog post, the 67-year-old author says "I won't make excuses. There are no excuses. No one else is to blame. Not my editors and publishers, not HBO, not [screenwriters] David [Benioff] and Dan [Brett Weiss]. It's on me. I tried, and I am still trying."

The author explains, "The days and weeks flew by faster than the pile of pages grew, and (as I often do) I grew unhappy with some of the choices I'd made and began to revise... and suddenly it was October, and then November... and as the suspicion grew that I would not make it after all, a gloom set in, and I found myself struggling even more. The fewer the days, the greater the stress, and the slower the pace of my writing became."

So where does that leave the novel? "I am months away still... and that's if the writing goes well ... I am not going to set another deadline for myself to trip over. The deadlines just stress me out." He adds, with finality, "It will be done when it's done."

After he finishes the novel, the last installment in the series, A Dream of Spring, is still on his plate.