Gotham by Gaslight, by Brian Augustyn and a pre-Hellboy Mike Mignola, holds a special place in Batman and DC Comics history. Released in 1989, the steampunk-flavored story -- which places Bruce Wayne in 1889, taking on Jack the Ripper in Gotham City -- is considered the first Elseworlds story in DC history, and is now the subject of an animated direct-to-home release feature adaptation.

The animated Batman: Gotham by Gaslight is slated for release in early 2018, and was the subject of a panel Friday afternoon at New York Comic Con, on the convention's main stage. In attendance: executive producer Bruce Timm, director/producer Sam Liu and screenwriter Jim Krieg.

The panel, moderated by publicist Gary Miereanu, started with a discussion of how to extend Gotham by Gasligh to a feature length given the brief source material. Timm said it'll include more characters than seen in the original comic.

"Because it was such a short length, the identity of who Jack the Ripper was, there was really only one suspect, really," Timm said, while the animated feature will include many suspects. "Some of them are red herrings, and maybe one of them actually is the Ripper."

Timm said he's not sure if Gotham by Gaslight will be rated PG-13 or R. "It's not an all-ages movie," Krieg said. "We don't want to hear from parents, 'I showed my children this Jack the Ripper story, and it wasn't appropriate at all!'"

"It's as bloody as it needs to be," Timm said of the film. "It's about this guy who is a serial killer." "There's more black ink than there is red ink in the making of hte movie," Krieg said. "It's bloody, but it's not like dissecting a frog. It's not CSI." "No, but there is at least one sequence that makes you squirm a little bit," Timm added. "Maybe two."

Timm said he's a huge fan of Mike Mignola's art, but it wasn't possible to exactly replicate his art style in animation. "We made a decision early on that to adapt his story absolutely faithfully would have taken more time and money than was able to us," Timm said. "It's not a direct adaptation of his visual style, but we definitely took some visual cues from what he did in the comics, and fused that with our traditional animation styles."

"We did do certain things that were a little bit differently than what we typically do," Liu added, speaking specifically of the depiction of Jack the Ripper. "We were trying to get as much shadow as we possibly could."

Following the opening comments, a clip from the feature was shown to the audience. In the scene, three street urchins -- clearly based on Dick Grayson, Jason Todd and Tim Drake -- who have been pressed into service as pickpockets, are confronted by Batman in the middle of an attempted mugging. He attacks the criminal that's taken charge of the boys, and directs them to go to an orphanage and turn around their lives.

Batman's eyes are visible in the Gotham by Gaslight costume, which Timm said was taken from Mignola's costume design from the comic.

"There's a real emotional arc for Bruce," Krieg said of the feature. "I think it's nice for us to see into him."

Bruce Greenwood voices Batman in Gotham by Gaslight, and Jennifer Carpenter voices Selina Kyle. Liu complimented Carpenter's performance and said, "She's not afraid to go really, really broad."

Timm said the Selina Kyle of Gotham by Gaslight is an actress/adventurer, and inspired by Sherlock Holmes character Irene Adler. "She's an equal to Bruce Wayne," Krieg said. "They're investigating this tragedy together."

Another clip is shown -- this one of Batman and Selina Kyle (not in a Catwoman costume, busing a whip) fighting Jack the Ripper in a slaughterhouse. Timm said the reason for the setting is because recently retired Warner Bros. animation veteran Alan Burnett said he always wanted to set a scene in a slaughterhouse.

Of the whip, Timm said, "She's not quite Catwoman, but she's close to it."

While Gotham by Gaslight is inspired by the fame real-life crimes of Jack the Ripper, Timm made it clear the feature isn't aiming for historical accuracy. "Hardcore Ripper-ologists are going to have a field day with all the inaccuracies and anachronisms," Timm said. "None of the victims are the real victims, and the timeline is completely different. But we did want to incorporate Victorian London elements into Gotham City, including the famous pea soup-fog they had in London those days."

Timm said a lot of the Gotham by Gaslight crew were fans of the show Penny Dreadful, and got to scratch a creative itch sparked by the Showtime series. Liu said the screenplay is "textured" with nods that place the dialogue in the period.

"Alfred's role in this movie is even more correct to the time period than in the modern day," Timm said. "No one has butlers these days, quite frankly. But in this movie, it totally, totally fits. We were delighted to have Anthony Head from Buffy playing Alfred. I think he's awesome in this movie."

In Gotham by Gaslight, the comic book character of Leslie Thompkins is "Sister Leslie," of the orphanage mentioned by Batman to the Robins. "She makes a strong presence in the movie," Krieg said. "All these characters seem to pop. I hope you love them."

"You want it to seem like a whole world," Krieg said. "Maybe enough for a whole other movie."

Other Elseworlds stories that the team might want to adapt? "Red Son!" multiple audience members shouted. "Red Son is at the very top of our list if we do another one," Timm said. "In a weird kind of way, it's sort of the opposite of this movie in scope and length. That would be a challenge, to get all of that story into one 70-minute movie." Another fan yelled Speeding Bullets, which Timm agreed could also make for a good animated feature.

One more clip was shown, of a dialogue-free action scene.

Moving to fan Q&A, an audience member asked about the "challenge" of depicting Batman without high-tech gadgets. Krieg said that it means the character has to rely further on his intelligence. "There's certainly a nod to all the Bat-gadgets, but the biggest gadget is under the cowl." Liu said it meant the film leans more on the character's origins as the World's Greatest Detective.

Krieg said the feature has "DC Comics Easter eggs, Jack the Ripper Easter Eggs and Sherlock Holmes Easter eggs." "This is Easter morning."

Any chance of an animated Batman: Red Rain? Timm said he's wanted to do a Batman/vampire story since Batman: The Animated Series, but standards and practices didn't allow that at the time. "Red Rain's one of them on our 'look at' list."

Is Joker in Gotham by Gaslight? "You've got to save something for the sequel," Timm answered.

A fan told Timm that she's more of a fan of the PG-rated animated films, and asks if there are plans for a lighter movie. "This entire line is kind of aimed at older fans," Timm said. "PG-13 is kind of our pocket. Some of them will skew more towards R, some of them won't be as extreme. It's a case-by-case basis. They're not going to be more family friendly overall, I don't think." Krieg used the opportunity to plug the all-ages animated series Justice League Action, which he produces.