Jon Snow’s meeting with Daenerys was spoiled months ahead of time, thanks to drones. Photo-Illustration: Maya Robinson/Vulture and Photo by SplashNews

On June 29, 2015, barely two weeks after Jon Snow was stabbed to death on Game of Thrones, a Twitter user named Joseph O’Rourke spotted Kit Harington in a Belfast airport. No offense to Belfast — a lovely city of farm-to-table restaurants, music-filled pubs, and hardly any sectarian violence — but there seemed to be only one reason for Harington’s presence in the Northern Irish capital, which serves as Thrones’ home base: Jon Snow was coming back from the dead. The actor would pop up in Belfast throughout the summer of 2015, always sporting Jon’s luscious locks, with each appearance in the city obsessively catalogued by the fan site Watchers on the Wall. By the time Harington was photographed in costume on the set of the Battle of the Bastards, the news only confirmed what dedicated WOTW readers had known for months.

Alongside podcasts like A Storm of Spoilers and seemingly every British tabloid in existence, Watchers on the Wall is one of the hubs of the Game of Thrones spoiler-industrial complex, a media machine that never stops churning. The site was established in 2014 by staffers who jumped ship from another site, Winter Is Coming, after a change in ownership. When Thrones is airing, WOTW acts like any other fan site, hosting recaps, essays, and podcasts; in the off season, though, it takes its game to a new level. The site’s small staff, most of whom have other jobs, spends the months between seasons analyzing casting notices, tracking the show’s cast on social media, and poring over local news from Croatia, Iceland, and Spain, where Thrones has filmed its various settings. If anyone’s going to break a piece of Thrones news, it’ll be WOTW.

At this point, the site gets most of its scoops from a stable of reliable insiders. “Most of them are people who are tangentially connected to people who are connected to people who are connected to the show,” says Susan Miller, the site’s editor-in-chief. “They’re casual friends who someone got drunk and bragged to. Or a neighbor who lives near a set and they become good at noticing the comings and goings.” Although the actual Thrones cast and crew sign NDAs with grievous financial penalties for leaking, their acquaintances are bound by no such contract.

As with any journalistic enterprise reliant on tips from the public, the risk of fake leads is very high, but WOTW tries to independently verify every single tip they receive. And at this point, Miller says the staff has a good ear for what rings false: “People come up with things that are blatantly fake. A lot of times you get these long and very detailed fantasies that are clearly fanfiction. Real information is more more direct, it’s much more logical. It’s not usually fan service.” That’s not to say their instincts are 100 percent accurate: Back when Miller worked at Winter Is Coming, she got a tip that the role of Tommen had been recast with actor Dean Charles Chapman, who had already had a small role as a Lannister cousin in season three. “We actually disregarded it at first because we thought they were trolling us,” she says. (They later posted it, after verifying the rumor wasn’t a goof.)

When everything lines up, though, it’s a rush. Take Euron Greyjoy’s appearance in season six. WOTW broke the news that Euron was being cast, but the production successfully managed to hide the identity of the actor playing him. It wasn’t until a source spotted the show filming on a Northern Irish beach that Pilou Asbaek’s casting was revealed — but first, they had to place the actor’s face. “I remember talking to the source, and they were trying to explain how they recognized Euron,” Miller says. “They were like, ‘It’s that guy from Borgen,’ [a Danish drama beloved by GOT casting director Nina Gold] but there are a million guys from Borgen.” Miller pulled up the show’s cast list, going over the actors one by one over the phone. “Finally, he gave me that name. It was a bit of a surprise. As a longtime book reader, I felt a connection to it. That was really exciting for me.”

Given the circumstances, HBO admits that it isn’t easy to keep all those secrets under wraps. “Game of Thrones is filmed on several continents with hundreds of cast and crew members so, though it would be ideal to not have spoilers online, it is very difficult to contain all information on a production of this scale,” says Jeff Cusson, HBO’s executive vice president of corporate affairs. “However, the record viewership this past season would suggest that even when details emerge it has minimal to no impact on the audience. We of course continue to work with production to limit to the best of our ability the release of information but also believe fans of Game of Thrones have very little appetite for it.”

With interest in Game of Thrones growing by the year, the production and the spoiler industry have been locked in a game of moves and countermoves. Paparazzi often follow the buses that shuttle the cast and crew out of Belfast on early-morning drives to location shoots; now, instead of heading straight to the set, the buses loop around in a holding pattern until the paps get the message. A few seasons back, passersby noticed that they could peek into the studio complex where the cast took smoke breaks; one of them took photos of actors in costume and sent it to WOTW. “The next day there was a partition,” Miller says with a laugh. “Every time we get information, they learn how to block us.”

Try as they might, the production has had a harder time combating spoilers that leak through the air. Thrones sets are constantly menaced by that 21st-century nuisance, drones, and rumor has it that the Daily Mail even hired a plane to fly over location shoots. (The Daily Mail did not return a request for comment.) Aerial photography spoiled Jon Snow’s appearance at the Battle of the Bastards in season six, as well as Jon and Daenerys’s meeting in season seven. “In Spain, we were being live-streamed while we were filming, from drones,” Liam Cunningham told RTÉ’s The Works Presents. “Everything we’ve done has been infiltrated, which is terrible.”

But if Thrones can’t prevent outdoor scenes from leaking, they can at least muddy the waters. As Kit Harington told Jimmy Kimmel, not every supposedly leaked scene from season seven was really in the script. In a time-consuming bit of misdirection, some were fake, including those photos of Jon petting a dragon head on the beach. (Miller notes proudly that WOTW didn’t fall for that one, since the dragons are actually played by green balls on sticks.)

The show has at times employed even more complicated fakes to mislead observers. When actress Sibel Kikeli visited the set in 2015, a year after her character Shae was killed off, she put on a costume apparently just to troll spoiler hunters. Sometimes, the production even takes a cue from its own scheming characters. Filming for the Battle of the Bastards, Miller recalls, was filled with “things that didn’t happen” in the actual show: “There were so many versions of what was going on, what the exact timeline of the battle was,” though some of that she chalks up to confused extras. In one instance, WOTW got a tip that the battle featured the dead bodies of two characters crucified on the Boltons’ flaming Xs. Because the news was so specific, Miller was wary it was a trap; the site ran the news, but left out the names of the characters in order to protect the source.

Covering Thrones’ seventh season presented a totally different challenge, as a summary of the major plot points hit Reddit months before the premiere. (The leak turned out to be accurate, with one or two exceptions. Miller suspects it came from an early version of the script.) According to Miller, only two WOTW staffers read the outline while everyone else intentionally stayed in the dark, though as it turns out, most of the leaks matched up with what the site found in its own reporting.

Even for those in the spoiler business, the leak seemed to cross a line. “That whole situation was unfortunate,” Miller says. “I do believe there’s such a thing as too many spoilers. People will read them and go, ‘I wish I hadn’t done that.’” Among those who’ve made it their life’s work, few would deny that spoilers can, well, spoil. Just like the game of thrones, the game of spoilers occasionally calls for a little bit of discretion.