A Song of Ice and Fire author George R.R. Martin talks about the Red Wedding in Game of Thrones season 3, and how he plans to end the book series.

Game of Thrones fans, both readers and the unsullied, were shocked and horrified by the events of season 3, episode 9, when Robb and Catelyn Stark were both murdered at the Red Wedding.

We’d like to say that it’s all rainbows and sunshine from here on out, but you know what they say: Winter is Coming. (Well… we guess they don’t say it anymore. Too soon?)

EW has spoken to A Song of Ice and Fire author George R.R. Martin about the shocking twist, and when he first decided it had to happen.

“I knew it almost from the beginning,” Martin says. “I killed Ned because everybody thinks he’s the hero and that, sure, he’s going to get into trouble, but then he’ll somehow get out of it. The next predictable thing is to think his eldest son is going to rise up and avenge his father. So immediately [killing Robb] became the next thing I had to do.”

However, even though he knew it had to happen, “That was the hardest scene I’ve ever had to write,” he admits. “It was like murdering two of your children.”

And he completely understands that readers (and now viewers) are upset. “Just as you grieve if a friend is killed, you should grieve if a fictional character is killed. You should care. If somebody dies and you just go get more popcorn, it’s a superficial experience isn’t it?”

Martin loves catching his readers off guard, and this means killing off the good guys. “I anticipate a bittersweet ending,” he says of the ending to the series, which culminates with the seventh book in the saga, A Dream of Spring.

We’ll have to wait a while to find out whether any Starks survive the series at all however, as Martin is still writing the sixth book, The Winds of Winter.

Next week’s episode of Game of Thrones is the season 3 finale, titled “Mhysa.” It airs at 9/8c on HBO.