[Warning: The following contains spoilers for the latest episode of Westworld, "The Winter Line." Read at your own risk!]

We finally know what happened to Drogon after he flitted away into the unknown in the Game of Thrones finale, and it's even grimmer (and, honestly, a bit more hilarious) than we expected. On Sunday, Daenerys Targaryen's (Emilia Clarke) beloved dragon flew from one HBO series to another when he appeared on the latest episode of Westworld, accompanied by two people you've probably heard of; as expected, Game of Thrones executive producers David Benioff and D.B. Weiss enjoyed a shared cameo on the sci-fi series, and it was the ultimate HBO crossover moment.

In the episode, Bernard (Jeffrey Wright) and Stubbs (Luke Hemsworth) were sneaking back into the park's tech corridors when they stumbled upon Benioff and Weiss' alter egos: two lab technicians working on transporting Drogon to a buyer in Costa Rica. As Weiss wielded a large power saw and discussed his plans to break the fire-breather into pieces, Drogon growled threateningly, which was a pretty tame reaction from him, all things considered.

<em>Westworld</em>Westworld

As for how the Game of Thrones mash-up came to be, Westworld co-showrunners Lisa Joy and Jonathan Nolan revealed that they have George R. R. Martin to thank for the inspiration. Nolan told Variety, "George had consistently since the first season said, 'We've got to do a tie-in with Game of Thrones.' People forget that George was originally a TV writer and he came up in the TV world in which you'd occasionally have these crossover shows, which the fans would f--ing freak out over. So, George had always been pitching the crossover show."

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When it came to getting Drogon on set, Joy and Nolan also explained that some serious maneuvering went into the effort. "I remember there was a whole big debate about which season dragon for its size because the dragon grew," Joy said. "There was some back and forth about whether Season 4 or Season 5 Drogon," added Nolan, "and some debate about how big the room was and what position the dragon could be in."

It's worth noting that Benioff and Weiss have always been friendly to cameos — and of course made their own on Thrones — but this particular appearance gave them a chance to sew up one of the loosest ends of Game of Thrones' final season, even if it's not exactly canon.

Westworld airs Sundays at 9/8c on HBO.

David Benioff and D.B. Weiss, <em>Westworld</em>David Benioff and D.B. Weiss, Westworld