Ahead of its Comic-Con International, not a ton was known about the upcoming third season of "Gotham." Speaking to the actors, CBR News had the opportunity to peel back the mystery of the DC Comics-based series' third year, as it brings in fresh elements from the comics -- like Harley Quinn, Killer Croc, Mad Hatter, the Court of Owls and Talon -- and builds on the development of burgeoning villains like the Penguin, the Joker and the Riddler.

In a video interview with CBR's Kiel Phegley (view in full above), David Mazouz (Bruce Wayne), Cory Michael Smith (Edward Nigma) and Sean Pertwee (Alfred Pennyworth) opened up about their characters' transformations as the Batman prequel series enters its third year and melds into the mythology we know and love.

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The cast discussed their enthusiasm over sharing more scenes together, and the series' structural shift from a police procedural to a traditional serialized drama.

"I was thrilled when we shifted from a more procedural crime show into a proper drama," Smith said. "With the catalogue of characters we have on the show, it's like...if we're not going to put them at the forefront, what are we doing? It's been so good to have the world feel like it's getting smaller."

Mazouz added, "We know each other so well...but we don't have scenes together!"

Pertwee discussed Alfred's badass side, which we got a healthy dose of in "Gotham" Season 2, and the key connection he has with Harvey Bullock. "Alfred knows -- he knows best. He really doesn't trust anybody. But there's no one really to lean on. The only other person he trusts is Lucius Fox, other than Master B. So he doesn't trust anybody, and he has this bushido type oath to protect Bruce for his entire life. And from that their relationship is formed...He's the observer in a lot of respects...There's a lot of similarities with Bullock and Alfred as well -- being a straight shooter. The writers and producers, and one of the showrunners, have given me that opportunity [to fight], and it actually gives much more of a reason for Alfred to be there as well."

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Describing how he feels the character is Bruce Wayne's enabler -- inadvertently, teaching him everything he needs to know to become Batman, Pertwee said, "...He's young Master Bruce's enabler, really. He didn't become Batman overnight. He learns -- he learned from cooking skills, to fighting skills, to manners, to dance -- everything. All of this information has come from one person, which is Alfred, from their relationship."

Smith delved into Nigma's transformation into "full-on Riddler," saying --he believes -- the character doesn't even know what's happening yet. The actor teased Nigma coming into his own in the third season, and learning to "run the show a bit."

"He's such a brilliant mind, and when he decided to frame Jim he came up with this brilliant elaborate plan. Which was by no means flawless -- but it was pretty darn good! He kind of went full-on Riddler, but he has no idea what that means."

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"As we move [forward], and he gets out of Arkham, and has this clean slate and decides what to do, he's embraced the darker side of himself and realized, in Arkham, he can make friends. He actually has the ability to make friends and kind of run the show a little bit. And also, he's aware of what his skill set is. Once he starts putting this together, and deciding 'this is my identity,' then he can eventually don the title of the Riddler. He doesn't know that the question mark is his emblem yet, but he's already used it."

Starring Ben McKenzie, Donal Logue, David Mazouz, Sean Pertwee, Robin Lord Taylor and Cory Michael Smith, "Gotham" returns Monday, September 19 at 8pm ET on FOX.