The first season of "Marvel's Agents of S.H.I.E.L.D." was eventful for a couple of reasons. In the fictional world of the Marvel Cinematic Universe, April's "Captain America: The Winter Soldier" feature film brought major upheaval to the small screen with the revelation that S.H.I.E.L.D. had long been manipulated from the inside due to an insidious Hydra infiltration -- leading to the rather bombastic dismantling of the organization featured in the TV series.

Over in the real world, the show received copious amounts of hype before launch -- it's not every ABC network drama that's tied into a multi-billion dollar movie franchise -- and some fans and critics were rather vocally disappointed when initial episodes didn't meet their expectations. And again, "The Winter Soldier" brought change, with many former skeptics expressing enthusiasm for the shifts the major plot developments brought to the series.

Late last month at Comic-Con International in San Diego, the cast and executive producers of "Agents of S.H.I.E.L.D." discussed the new season with members of the press. Season two will include plenty of additions to the cast in both heroic and villainous roles, including Lucy Lawless, Adrianne Palicki, Kyle MacLachlan, Henry Simmons and Reed Diamond.

"Because S.H.I.E.L..D. has crumbled, because we're left with limited resources, Coulson may have to reach outside of the organization -- and that may entail some uneasy alliances," Maurissa Tancharoen, who serves as showrunner along with Jed Whedon, told CBR of the new additoins. "Even though we're bringing people into the fold who are there to help us, we might not necessarily see eye to eye all the time. So there will be lots of conflicts."

Plenty of new faces have been announced as joining "Agents of S.H.I.E.L.D." season two, but it's not yet known how much recognizable characters from the Marvel Studios films may be seen -- the first season included appearances from Nick Fury (Samuel L. Jackson), Maria Hill (Cobie Smulders) and Sif (Jaimie Alexander).

"There are a few other Asgardians we'd love to come into play," Tancharoen said. "That's something that we absolutely love doing, and it's something we feel very privileged in doing on the show. No other show has the opportunity to pull from such a vast [comic book] universe, as well as the Cinematic Universe. There are many characters we want to play with."

"We also have an advantage, because everybody wants to be in Marvel movies," Whedon said. "Even in these tiny roles, you'll see, 'Wait, that's a fantastic actor -- let's have him have a whole arc in our show!" We reap the benefits of the Marvel Universe."

Series star Clark Gregg, who plays Agent Phil Coulson -- a character first seen in 2008's "Iron Man," the film that kicked off the Marvel Studios era -- has admitted his status as a long-time comic book fan, and never been shy about his enthusiasm that he's gotten to do as part of the Marvel world. For him, getting to rebuild S.H.I.E.L.D. -- something Nick Fury personally tasked him with at the end of season one -- is the latest unexpected acting opportunity in the role "that just blows [him] away on a daily basis."

"I do like the idea that he's got the people from his first team from last year," Gregg said to CBR. "Skye's clearly an important character to him. May is someone he's worked out his demons with and can trust. And now they've got to rebuild S.H.I.E.L.D. from the ground up. That means making some new S.H.I.E.L.D. agents, and I assume, finding out some new Hydra supervillains."

The new season won't start exactly where the last one left off, according to Gregg, as the show will reopen "months later," with the rebuilding process already in motion.

"The monumental nature of that task is made very clear almost immediately, because you realize everyone -- US government, US military and other wise -- wants to arrest us," Gregg said. "S.H.I.E.L.D.'s illegal. We have very few resources. Everything we're going to do involves dealing with, still, finding out who's Hydra and who's not amongst our friends. To rebuild S.H.I.E.L.D., we're going to need some old friends to prove themselves, some new friends, and we're going to have to do it in a way that's very back alley, old school -- feels very brass knuckles, Cold War spying for me."

While both "Thor: The Dark World" and "Captain America: The Winter Soldier" hit during the first season run of "Agents of S.H.I.E.L.D.," the next Marvel Studios film on the release schedule is "Avengers: Age of Ultron," scheduled for May 1, 2015 -- likely towards the end of the show's second season, and presumably freeing the show somewhat from a similar seismic impact.

"No movie's going to do to us what 'Cap 2' did," executive producer Jeffrey Bell said. "That I know of. And if it does, cool. It's fun to tie-in. I think people really enjoy that. We like trying to play to that."

Ratings remained solid for the first season of "Agents of S.H.I.E.L.D.," though the audience dropped from its splashy debut. The season premiere attracted a reported 17 million in the US when combined with DVR viewers, while this past May's season finale netted 8.58 million. Jeph Loeb, head of Marvel Television, acknowledged the challenge of growing the audience in the new season, and said the show's shift from 8 p.m. to 9 p.m. may be a needed boost.

"Our challenge now, is also to build our audience," Loeb said. "To get more people involved. Some of that is going to happen by people watching the show during the summer -- there's a lot of shows in their second season that get a little bit of a boost.

"Secondarily, we are moving to a 9 o'clock time slot, and that time slot gives us an opportunity to have a lead-in, as opposed to coming off of 'Wheel of Fortune.' We're now really part of a night, as opposed to kicking off a night. And that's the fun of working on network."

When "Agents of S.H.I.E.L.D." began, a frequent complaint was that despite being set in the same continuity, the series wasn't enough like the Marvel movies -- something fairly unavoidable due to realities like budgets and actor availabilities. Loeb expressed pride in the show now being accepted on its own merits -- starring a cast of previously unseen characters, other than Coulson -- and generating enthusiasm for what it is, not what it isn't.

"It really is great that people care about the characters," Loeb said. "When the show came on the air, there was a lot of, 'Is the Hulk going to be on the show?' 'Is Iron Man going to be on the show?' You know what people want now? 'What's happening with Ward?' 'We want to know who Skye's father is!' 'Why is Coulson writing on the wall?' That's a major shift in terms of what our audience wants, and we can deliver on that in spades. Not so much the Iron Man part."

"We don't have to work as hard for you to care about them, because mostly people now care about them," Bell said. "That was the hardest part. Now we can rely a little bit on that goodwill, and just focus on telling really good stories."

The second season of "Marvel's Agents of S.H.I.E.L.D." is scheduled to debut Tuesday, Sept. 23 on ABC.