Kit Harington as Jon Snow, with direwolf Ghost. Helen Sloan/HBO Warning: spoilers ahead for Sunday's episode of "Game of Thrones," "Battle of the Bastards."

While "Game of Thrones" delivered an epic penultimate episode on Sunday, many fans noticed that something was missing.

Jon Snow's (Kit Harington) direwolf, Ghost, is rarely far away from her master, especially when he's in danger. Yet, Ghost was nowhere to be found on this week's bloody episode, "Battle of the Bastards."

So why did Jon's best friend not make it to the battlefield?

"[Ghost] was in there in spades originally, but it’s also an incredibly time consuming and expensive character to bring to life," the episode's director Miguel Sapochnik told Business Insider on Monday. "Ultimately we had to choose between Wun-Wun and the direwolf, so the dog bit the dust."

"Battle of the Bastards" was a complicated and expensive episode to produce. While a typical episode takes one to two weeks to shoot, Sunday's episode shot for 25 days, Entertainment Weekly reported. That included 600 crew members, 500 extras, 70 horses, and 25 stuntmen and women. Its price tag could lie somewhere between $11 million and $25 million.

Ian Whyte as Wun Wun HBO Still, just because Ghost had to be dropped doesn't mean the production made the easier and cheaper decision by bringing Wun Wun, the Wildling giant loyal to Jon Snow, to the battlefield.

"Anything with the giant is a challenge," Sapochnik told us, "because he’s not there, and you have to shoot multiple layers for each shot, and get extras to react to something that doesn’t exist, and then shoot the actual giant played by Ian Whyte months later on a green screen stage."

Plus, Wun Wun ended up giving his life to place the Starks back in Winterfell. While definitely sad, at least we know Ghost is alive and well.