Jeph Loeb -- acclaimed comic book writer and head of Marvel Television -- is set to take the stage Friday afternoon at Ballroom 20 at Comic-Con International in San Diego, along with cast members from "Marvel's Agents of S.H.I.E.L.D." and Marvel's Agent Carter.

The panel started with a "Marvel" logo on the screens accompanied by some ominous music, before Loeb joined the stage to enthusiastic applause. "You're going to be seeing stuff that nobody else gets to see," he told the crowd.

Loeb said that due to the actions of Hydra, fans learned last season, "don't trust anybody." He surveyed the crowd asking if they were fans of S.H.I.E.L.D. -- and there were plenty -- or fans of Hydra -- there were a few (and some boos). Loeb unbuttoned his shirt to reveal a Hydra t-shirt underneath.

Reminding the crowd of the "Agents of S.H.I.E.L.D." second season premiere date (Sept. 23) and new time slot (9 p.m.), Loeb turned to "Agent Carter," and brought out showrunners Tara Butters and Michele Fazekas, plus "Captain America: The First Avenger" and "Captain America: The Winter Soldier" screenwriters Christopher Markus and Stephen McFeely (who wrote the show's pilot, Marvel Studios co-president (and "Agent Carter" one-shot" director) Louis D'Esposito, plus series star Hayley Atwell.

Loeb asked the showrunners how they landed on the series. Fazekas said ABC approached them as the first season of "Resurrection" was about to wrap. "We didn't even have to think about," she said. "It was kind of a dream come true."

"Having this show is a great opportunity to go back and mine this really rich opportunity we didn't really get an opportunity to play with," Markus said of the creative prospects of the series. "In the pilot, she will have equaled her entire time on screen in the Marvel Universe," McFeely added.

Atwell said she's excited to see Peggy Carter "develop as a human being as well as a super-spy. You get to see costs, psychology and emotionally."

The show takes place in 1946, Loeb said. "The story of what went on in the very beginning, and how Peggy's concerns about what the world should be and how to make the world a better place, are so many of the themes of this show," he said.

An "Agent Carter" trailer, composed of sequences from "Captain America: The First Avenger" and "Agent Carter," archival footage and faux-headlines, played. Carter's narration: "The word is changing. And if history has taught us anything, it's that freedom is not free. Sometimes the best thing you can do is start over. Welcome to the SSR."

Text of the trailer read, "discover a different side of the Marvel Universe" and "go back to where it all began," with files reading "Zodiac" and headlines of "Stark Industries Under Investigation."

D'Esposito disclosed that "Winter Soldier" directors Joe and Anthony Russo will direct the second and third episode, and "First Avenger" director Joe Johnston is scheduled to helm the fourth.

First fan question -- from an Agent Carter cosplayer -- asked about the importance of accurately portraying the character's military past. "I think we've got a fantastic research on board, just to make sure that every reference we make is backed up with authenticity," Atwell answered. "That's also kind of my job as well, to make her as accurate as I possibly can, so she's relatable."

Second question -- from another Agent Carter cosplayer -- asked if Dominick Cooper would return as Howard Stark. Loeb said he speaks for the panel that it wold be "fantastic if that could happen."

Third question -- from yet another Agent Carter cosplayer -- asked if there would be more female characters on the show. Fazekas said much of the show's dramatic tension comes from Carter being a woman dealing with what's still very much a man's world (as seen in the "Agent Carter" one-shot), but there will be more female characters "both good and bad," in the series.

Fourth question -- this time from a Winter Soldier cosplayer -- asked Atwell about how she feels playing a female action star. Atwell called it a "privilege," and said, "when I was a little girl, there were parts like Peggy on films and television that I aspired to be. it's a huge moment to be able to play someone that hopefully young women will look up to as a role model."

With the "Agent Carter" section wrapped, Loeb introduced a sizzle reel recapping the first season of "Agents of S.H.I.E.L.D."

This led to the introduction of the "Agents of S.H.I.E.L.D." crew: executive producer Jeffrey Bell, showrunners Maurissa Tancharoen & Jed Whedon, plus cast members Elizabeth Henstridge, Iain De Caestecker, Chloe Bennet, Ming-Na Wen, Brett Dalton (wearing a Hydra t-shirt) and series lead Clark Gregg.

Loeb started the discussion by asking De Caestecker how he (more precisely, his character) now feels about Grant Ward, given the character's betrayal last season. "I guess it's fairly safe to say that I'm heartbroken," De Caestecker said, to laughs.

Loeb asked Henstridge how she feels after a year of playing Simmons. "I feel like I've gotten more intelligent," Henstridge joked. "I've got a whole new family," she continued, speaking of the folks alongside the panel with her.

Turning to Bennet, Loeb asked if Skye will be more involved as an active S.H.I.E.L.D. agent this coming season. "I don't know Jeph, you tell me," Bennet said. "I believe so. I think there are going to be some changes. She's been through a lot. She was betrayed by somebody."

"I still ship SkyeWard," Bennet continued. "But it's going to take a while. Until then, I'm really OK with Skimmons." (Skye and Simmons.)

Dalton told the story of how he was told by the executive producers that his character would be revealed as an undercover Hydra agent, saying that when they told him they needed to talk to him, he was worried he might be getting fired. But he's pleased with the results. "I got to work with Bill Paxton," Dalton said. "It was quite a turn, and I have embraced it, wholeheartedly. I hope there's some Team Hydra out there, as well," he told the crowd.

"I think once [Dalton] became a villain, he turned up the sexy a few notches," Tancharoen said.

When asked by Loeb about Coulson taking on the role of Director of S.H.I.E.L.D, Gregg joked that he and Coulson are slowly merging, and both of their reactions is, "squee."

Tancharoen confirmed the recent reports that Lucy Lawless will appear on "Agents of S.H.I.E.L.D." "She will play a long-time S.H.I.E.L.D. veteran. She's tough. She may have a knife that's always by her side. Her name is Isabel Hartly, and you'll be seeing her pretty soon."

Bell revealed that actor Nick Blood will join the show as Lance Hunter, an established Marvel character traditionally depicted as the director of British organization S.T.R.I.K.E. On "Agents of S.H.I.E.L.D," he'll be a mercenary that Coulson turns to for help.

Additionally, actor Reed Diamond will play Daniel Whitehall, a character from "Secret Avengers. "He's one of our Hydra baddies early on," Whedon said.

Following those announcements, a blooper reel from "Agents of S.H.I.E.L.D." season one played on the screens.

A quick round of fan Q&A included a young child dressed as Agent Coulson, the panel asked if they would accept Ward if he could be redeemed (something of a mixed reaction from the cast), how Bennet would feel if her character was revealed as Jessica Drew (she said that she's nearly as in the dark on her character's origins as the fans are ).

The panel ended with a short video of Patton Oswalt, in character as Billy Koenig (later joined by another identical sibling), comedically telling the crowd about the importance of the "security lanyards" passed out to audience members during the panel -- but most importantly mentioning the character name "Bobbi Morse," best known in Marvel Comics lore as Mockingbird. A frequent member of the Avengers, a TV show starring the character had been in development at ABC Family. Here's the teaser video, courtesy of Entertainment Weekly: