For its final season's epic, climactic battle, "Game of Thrones" is going deep — Helm's Deep.

The 40-minute scene in "Lord of the Rings: The Two Towers," which may be the longest battle in the history of film, served as inspiration for "Game of Thrones" director Miguel Sapochnik, as an extensive feature in Entertainment Weekly.

The battle, which pits the Night King's army against the allies led by Daenerys Targaryen and Jon Snow, required 11 weeks of grueling night shoots. It lasts the entire episode and "is expected to be the longest consecutive battle sequence ever committed to film."

“What we have asked the production team and crew to do this year truly has never been done in television or in a movie,” said co-executive producer Bryan Cogman. “This final face-off between the Army of the Dead and the army of the living is completely unprecedented and relentless and a mixture of genres even within the battle."

Sapochnik is no stranger to shooting big fights for "Game of Thrones," having previously directed "Hardhome" and "Battle of the Bastards." But this one was on a completely different scale, as it involved nearly all of the major cast members.

“The [GoT battles] I’ve done previously were generally from Jon’s perspective,” Sapochnik noted. “Here I’ve got 20-some cast members and everyone would like it to be their scene. That’s complicated because I find the best battle sequences are when you have a strong point of view."

One of those stars, Maisie Williams (Arya Stark), was warned by Sapochnik to start training a full year before filming.

"I skip the battle every year, which is bizarre since Arya’s the one who’s been training the most,” she said. “This is my first taste of it. And I’ve been thrown in at the deep end.”