We saw some killer stuff at Wondercon this weekend — but this intense, gruesome scene of a man turning into a werewolf in Hemlock Grove might be the craziest. Seriously, just watch and see for yourself. Oh, and the video and what follows are a bit spoilery.

Hemlock Grove, coming to Netflix April 19, is the TV version of a novel by Brian McGreevy, and it's produced by Eli Roth — who directed the pilot. All the episodes are becoming available at once, in all territories, so you don't have to wait to see what happens next. In addition to the clip above, we also saw a sizzle reel, which gave a general sense of spookiness and sexiness, and showcased the incredible cast, which includes Famke Janssen, Dougray Scott and Battlestar Galactica veterans Aaron Douglas and Kandyse McClure.

Roth told the panel that he was always interested in doing a horror TV show, but had some concerns. Because what makes horror great is that you can kill off your characters at any minute. And what makes television great is that you follow the same characters week in and week out. Roth never figured out how to square that — but now that television has evolved with things like Game of Thrones and Boardwalk Empire, you can do more long-form storytelling in the medium.

Hemlock Grove is more like a 13-episode movie than a TV show, especially since Netflix will let you watch all the episodes in one go, said Roth. According to the producers, they were able to expand on some stuff in the novel, and add some cool stuff — including one thing that will be an enormous surprise to fans of the book.

At the heart of Hemlock Grove is the Godfrey family, with its twisted and unhealthy relationships. Janssen plays Olivia Godfrey, whom she described as "complex and manipulative." One of her children is Roman, played by Bill Skarsgård, and she also has a very troubled, complex relationship with Dr. Norman Godfrey, played by Dougray Scott. Her first husband committed suicide, and it was probably partly Olivia's fault.

Scott said his character is already kind of a morally dubious figure since he's sleeping with his dead brother's wife — and like all the characters on this show he doesn't turn out to be who you expect.

Skarsgård added that the mother-son relationship is "really weird" and "they're constantly bothering each other." Roman is a "disturbed" young kid, and a "super complex character, trying to battle this darkness growing inside of him."

Meanwhile, Aaron Douglas said Sheriff Sworn is confronted with a killing in his town — and he doesn't believe there's anything supernatural going on, he keeps eliminating other possibilities, like psycho killers, packs of wild dogs, or "a great white shark in the middle of the park." The sheriff does not want to believe there's anything supernatural going on, because that's "anathema."

McClure plays Dr. Chasseur, who comes to Hemlock Grove a few episodes in, to hunt and track the supernatural creature that's responsible for the killing. She's very single-minded and obsessive, and only interested in the townspeople in as much as they can help her obtain her goal. But her character gets some great scenes with the Sheriff, and she and Douglas both said how great it was to get to play off each other after never sharing any scenes on BSG.

Just like on BSG, Douglas said he got his scripts every week and immediately flipped to the end to see if his character was still alive at the end of the episode.

Landon Liboiron, who you can see turning into a werewolf in the clip above, plays Peter, the gypsy who comes to town and is an instant source of fascination for Letha Godfrey (Penelope Mitchell). Peter has been an outsider his entire life, so he's used to being isolated — but when he becomes a murder suspect, it's his biggest fear coming to life. He has to choose whether to stay or run.

When Roman first meets Peter, they have an instant connection, said Skarsgaard — and Roman is convinced they're going to do great things together, which might mean teaming up to solve the murders. (And this is before he knows Peter's secret, obviously.)

The whole show is "in essence, sort of a character piece," said Janssen, with the characters' interactions driving the story over 13 episodes. There's a "Twin Peaks quality to it," and for people like her, who never knew how to fit into the traditional model of television, it's a great chance to do something different. The show is "complicated" and "tempestuous," added Scott.

The ability to "binge watch" the show is one of the great strengths of the Netflix approach, said producer Mark Verheiden (BSG, Falling Skies). "That's the new way of watching television." This also meant they had no commercial breaks, and episodes could run as long as they needed to. And they didn't feel the need to make each episode self-contained, with its own "beginning, middle and end."

Towards the end of the panel, they showed the video you saw above, of the werewolf transformation. Roth talked a lot about how he wanted to "go practical" as much as possible with that sequence. They went to Greg Nicotero (Walking Dead) and Howard Benger, asking for help creating a transformation that feels both violent and visceral. "I want the 14 year olds who watched Twilight and saw that shirtless boy to be actually horrified," added Roth. They spent eight days just filming the transformation.

And the thing at the end, where the wolf eats "its own placenta," was something Roth really wanted. He wanted the transformation to be "sort of like epilepsy," something so painful you can't even remember it afterwards — but also natural and satisfying. A "weregasm." And since it happens every month, it's like "a werewolf period. It's like a baby being born, if a baby could shake off its own placenta."

They had a lot of discussions about what happens when the human eyes pop out — does he then grow a whole new set of human eyes when he turns back into a human? But it sounds as though we don't actually get to see that on screen.

Liboiron said he was really worried about looking foolish during that sequence, but they shot it in pieces and "they just let me go for it, I guess — and I just did the best I could." When his arm punches down, they used loose pigskin for his arm, so it would feel like the skin was loose and shaky.

Skarsgård said it's an intense thing for Roman to watch that happen — and most people would run away if they saw a guy turning into a wolf. But Roman is "so special and supernatural in his own way that he is so amazed by this. He has never seen something so beautiful in his own life."

Someone asked Roth about his The Bad Seed remake — and he said it's dead. "My original pitch to Warner Bros was, 'I'd like to kill more children than Schindler's List.'" And for some reason, the studio wasn't into that. He wanted it to be like Edward Gorey's The Gashlycrumb Tinies, but it ended up not flying. But meanwhile, he's doing a Dracula movie — co-written by Hemlock Grove author Brian McGreevy.