Courtesy of Gene Page/AMC

Who did Negan (Jeffrey Dean Morgan) kill in the season six finale of AMC's The Walking Dead?

That's the biggest burning question for the zombie drama heading into October's season seven premiere. With filming already underway in Atlanta, AMC is going to greater lengths than usual to protect the massive reveal.

Season six ended with Carl (Chandler Riggs), Rick (Andrew Lincoln), Michonne (Danai Gurira), Eugene (Josh McDermitt), Maggie (Lauren Cohan), Sasha (Sonequa Martin-Green), Daryl (Norman Reedus), Arron (Ross Marquand), Rosita (Christian Serratos), Abraham (Michael Cudlitz) and Glenn (Steven Yeun) all lined up before the charming villain and his barbed-wire-covered bat, Lucille, with Negan taking a deadly swing at one of them.

Sources tell THR that each of the 11 castmembers involved have already filmed a death scene. The Walking Dead producers and the episode director will then work with the show's editors and pick the character who does indeed die.

Season seven of The Walking Dead will pick up immediately with Negan's deadly swing, and as Morgan said, "You'll see who was at the end of that bat and what happened from there," while series creator/EP Robert Kirkman has said that Negan's victim is "beloved to everyone." For those who haven't read the comics on which the series is based [spoilers ahead], the landmark 100th issue sees Negan beat Glenn to death with Lucille.

The extra measures come as diehard fans continue to line Atlanta locations looking for a glimpse of their favorite stars and an early preview of what to expect from the new season — or to be outright spoiled with whom Negan killed. Some have gone so far as to use drones to capture images from production — something that showrunner Scott M. Gimple struggles with.

"With the advent of drones, it can become such a game of cat and mouse that as far as sneaking a peek at the actors walking to set, we want to just keep our actors safe and the people who might be looking safe — like [when they're] in the street," he told THR last summer. For her part, co-star Martin-Green noted that some actors have to be covered in hoods or moved around the locations in costume in order to protect who's still alive on the series. "Sometimes you can tell a specific story point based on what someone's wearing or what their makeup looks like — so in that case, we do what we can to cover in order to protect the story," she said last year.

Below, THR takes a look at some of the other big burning questions heading into season seven of The Walking Dead with the trailer and premiere date expected to be announced in July at Comic-Con.