October 2017: The Table Read When Kit Harington entered the conference room, he had no idea what to expect.

The final season’s scripts had been emailed just a couple of days earlier, sending the Game of Thrones cast into a reading frenzy. Like millions of fans around the world, the actors had been waiting nearly a decade to learn their characters’ fates. The entire six-episode season arrived at once, protected by layers of password security.

Sophie Turner flew through her copies in record time, quickly messaging the producers her reaction. “It was completely overwhelming,” says the actress, who plays Sansa Stark. “Afterwards I felt numb, and I had to take a walk for hours.” Others, like Emilia Clarke (Daenerys Targaryen), first had to hurry home to get some privacy. “I turned to my best mate and was like, ‘Oh my God! I gotta go! I gotta go!’” she recalls. “And I completely flipped out.” She then settled in for a reading session with a cup of tea. “Genuinely the effect it had on me was profound,” Clarke adds. “That sounds insanely pretentious, but I’m an actor, so I’m allowed one pretentious adjective per season.” Peter Dinklage, meanwhile, broke his years-long habit of checking immediately to see if Tyrion Lannister survives. “This was the first time ever that I didn’t skip to the end,” he says.

Even showrunners David Benioff and Dan Weiss were uncharacteristically anxious, wondering how the actors would react to the climactic twists. “We knew exactly when our script coordinator sent them out, we knew what minute they sent them, and then you’re just waiting for the emails,” Benioff said.

The cast then journeyed to Belfast to gather in a production office for the formal read-through. By then, everybody knew the tale that was about to unfold, with two notable exceptions: Davos Seaworth actor Liam Cunningham (“The f—ing scripts wouldn’t open, the double extra security!” he grouses) and Harington, who outright refused to read anything in advance.

“I walked in saying, ‘Don’t tell me, I don’t want to know,’” Harington says. “What’s the point of reading it to myself in my own head when I can listen to people do it and find out with my friends?” So, yes: Jon Snow, quite literally, knew nothing.

Benioff and Weiss opened the proceedings by asking the cast to refrain from doing anything during filming or afterward that might reveal even the tiniest spoiler (“Don’t even take a photo of your boots on the ground of the set,” one actor recalls being told). And then, seated around a long table scattered with a few prop skulls, the cast read aloud the final season of Game of Thrones.

At one point, Harington wept.

Later, he cried a second time.

Image zoom Helen Sloan/HBO

September 2012: It’s Impossible After the table read, the Game of Thrones cast spent 10 months filming just six episodes of television. But the season actually took far longer to pull off. GoT’s final chapters have been in the works for years. To better understand what’s ahead, let’s first go back to EW’s season 3 set visit and this never-before-revealed conversation with Benioff and Weiss…

The production camper was like many others on the set — barren, cramped, cold, utilitarian, with dirt on the floors from muddy boots tramping in and out all day. The showrunners sat on the same side of a tiny dinette booth while the wind coming off the Northern Ireland bay howled outside. They were already thinking about their final season, and it worried them.

During its second season, the fantasy drama averaged 10.3 million viewers across all platforms. That was enough to ensure they were eventually going to finish the series, yet that inevitability was also the problem. Because when they first pitched Thrones to HBO, they hadn’t exactly been honest. And now they were working every day toward a finale that was impossible to make.

“The lie we told is the show is contained and it’s about the characters,” Benioff said, which was at best half true. The epic fantasy was very much about its ensemble cast, but it’s also the least “contained” series ever made. “The worlds get so big, the battles get so massive.”

Author George R.R. Martin, whose series of novels forms the basis for Thrones, had revealed to the duo the broad strokes of how his Song of Ice and Fire saga secretly ends, including a description of an epic final battle that’s been teased from the show’s very first scene. But this climactic confrontation was miles out of reach for a series that cost about $5 million per episode. “We have a very generous budget from HBO, but we know what’s coming down the line and, ultimately, it’s not generous enough,” Benioff said.

So the producers had an idea: The final season could be six hours long and released as three movies in theaters — just like Martin’s best-known influence, The Lord of the Rings. It’s not that the duo wanted to make movies per se, but it seemed like the only way to get the time and money needed to pull off their finale. “It’s what we’re working towards in a perfect world,” Weiss said. “We end up with an epic fantasy story but with the level of familiarity and investment in the characters that are normally impossible in a two-hour movie.”

The flaw in this plan was that HBO is about serving its subscribers, not taking gambles at the box office. Behind the scenes, the network brass gently shot down the movie idea. But executives assured Benioff and Weiss that they would eventually have everything they needed to make a final season that was “a summer tentpole-size spectacle.”

Years later, the producers would strike a deal with the network to spend two years on a shortened season 8 that would cost more than $15 million an episode. You could say HBO made good on that promise from 2012, and the showrunners will happily give the network full credit. “They put their money where their mouths are — literally stuffed their mouth full of million-dollar bills, which don’t exist anymore,” Weiss quips.

But it’s probably more accurate to say that since season 3, Benioff and Weiss willed their ambitious final season into reality the hard way: by growing Game of Thrones into the biggest show in the world, a hugely profitable pop culture and merchandising sensation with more than 30 million viewers an episode and a record number of Emmys. Only with that kind of leverage do your towering ambitions begin to look like reasonable requests.

In fact, the GoT team was so successful that the biggest sticking point in the agreement was persuading HBO to halt the series. “We want to stop where we — the people working on it, and the people watching it — both wish it went a little bit longer,” Benioff says. “There’s the old adage of ‘Always leave them wanting more,’ but also things start to fall apart when you stop wanting to be there. You don’t want to f— it up.”

That concern — a constant desire to conclude the show on the strongest possible note — is something we heard over and over from the cast and crew when we visited the GoT set for the last time.

Image zoom HBO

March 2018: The final season Arriving at the studio gate, I’m halted by a guard and asked to scan my badge, a security upgrade from past years. Then I’m asked for my phone, and the guard covers its cameras with stickers — that’s new too. Along with an HBO escort, I walk inside an enormous hangar that’s so large it’s where the RMS Titanic was painted.

What’s being filmed here is episode 6, the series finale. Like Harington going into the table read, I don’t know anything about the final season’s storyline. I look around at a meticulously constructed set that I’ve never seen on the show before. Several actors are performing, and I’m stunned: There are characters in the finale that I did not expect. I gradually begin to piece together what has happened in Westeros over the previous five episodes and try not to look like I’m freaking out.

There is absolutely nothing more that can be said about that scene at this time.

A word about spoilers: The cast is used to keeping story secrets, yet they’ve never sounded so anxious about it. “There are moments where you don’t trust yourself to have this in your brain,” says Joe Dempsie, who plays Gendry. “You’re in possession of something millions of people want to know. It’s such a bizarre feeling. And between now and when it comes out, I’m gonna be drunk at some point.”

So far, at least, the team has done a far better job than in previous years at keeping the story under wraps, even while drunk. Theories abound online, but they are guesses. A purported script leaked to Reddit, but here’s a way to spot a fake — real Game of Thrones scripts don’t say “Game of Thrones” on them. “Drone killer” guns were used to guard against any peeping robots attempting to fly over the set. Production documents stating which actors were required to be where and when used code names (Clarke, for example, was “Eldiss”). “It gets highly confusing when you need to remember who is who,” Turner says.

Benioff and Weiss’ next gig is writing a new Star Wars film, and they received some final-season secrecy tips from The Last Jedi director Rian Johnson and producer Kathleen Kennedy. “They’ve given us a lot of hints about how to lock things down, things we never would have thought of or didn’t know were possible,” Weiss says.

At some point HBO will release a proper final-season trailer revealing more. Until then, here’s some basic setup we can tell you: Season 8 opens at Winterfell with an episode that contains plenty of callbacks to the show’s pilot. Instead of King Robert’s procession arriving, it’s Daenerys and her army. What follows is a thrilling and tense intermingling of characters — some of whom have never previously met, many who have messy histories — as they all prepare to face the inevitable invasion of the Army of the Dead.

“It’s about all of these disparate characters coming together to face a common enemy, dealing with their own past, and defining the person they want to be in the face of certain death,” co-executive producer Bryan Cogman says. “It’s an incredibly emotional, haunting, bittersweet final season, and I think it honors very much what George set out to do — which is flipping this kind of story on its head.”

How these fan favorites get along drives much of the drama this season (okay, here’s one specific tease from the premiere — Sansa isn’t thrilled that Jon bent the knee to his fancy new Targaryen girlfriend, at least not at first).

Image zoom Helen Sloan/HBO

The drama builds to a confrontation with the Army of the Dead that’s expected to be the most sustained action sequence ever made for television or film. One episode — the same that Benioff and Weiss were concerned about pulling off so many years ago — is wall-to-wall action, courtesy of “Battle of the Bastards” director Miguel Sapochnik.

Last April a crew member revealed that Game of Thrones had wrapped 55 night shoots while filming a battle. Media outlets around the world ran stories saying the final season’s battle took twice as long as the 25-day shoot for season 6’s climactic Battle of the Bastards. This wildly understated what really happened. The 55 nights were only for the battle’s outdoor scenes at the Winterfell set. Filming then moved into the studio, where Sapochnik continued shooting the same battle for weeks after that.

“It’s brutal,” Dinklage says. “It makes the Battle of the Bastards look like a theme park.”

The battle doesn’t have just one focus, either, but rather intercuts between multiple characters involved in their own survival storylines that each feels like its own genre. “Having the largest battle doesn’t sound very exciting — it actually sounds pretty boring,” Benioff says. “Part of our challenge, and really, Miguel’s challenge, is how to keep that compelling… we’ve been building toward this since the very beginning, it’s the living against the dead, and you can’t do that in a 12-minute sequence.”

To help pull it off, the production hugely expanded its set for the Stark ancestral home of Winterfell, adding a towering castle exterior, a larger courtyard, and more interconnected rooms and ramparts. Strolling around the new Winterfell is like wandering a sprawling, immersive medieval resort compared with its previous Days Inn-like scale. The ground is covered with snow and blood. The air is thick with smoke from the fire pits. You can turn any direction and only see more Winterfell. It’s easy to feel like you’ve somehow wandered into Westeros.

The Winterfell expansion is just a small example of how every element of the production was heightened this year in an effort to “not f— it up.” Scenes that normally might take a day to film now took several. “[Camera] checks take longer, costumes are a bit better, hair and makeup a bit sharper — every choice, every conversation, every attitude has this air of ‘This is it,’” Clarke says. “Everything feels more intense. I had a scene with someone and I turned to him and said, ‘Oh my God, I’m not going to do this ever again,’ and that brings tears to my eyes.”

Lena Headey, who plays Cersei Lannister, agrees: “There was a great sense of grief. It’s a huge sense of loss, like we’ll never have anything like this again.”

More tears, like during the table read.

You know, Harington will actually reveal why he cried that second time.

“The second time was the very end,” Harington says. He’s referring to when the cast reached the last page of episode 6, and what the showrunners wrote there at the bottom.

“Every season, you read at the end of the last script ‘End of Season 1,’ or ‘End of Season 2,’” Harington says. “This read ‘End of Game of Thrones.’” For more on Game of Thrones, pick up the new issue of Entertainment Weekly on stands Friday, or buy it here now. Don’t forget to subscribe for more exclusive interviews and photos, only in EW. And follow @jameshibberd on Twitter for final season updates.