'Marvel's Agents of S.H.I.E.L.D.' Plot Spoilers, Cast News: Clark Gregg Talks About Introduction of Inhumans

With only about a day to wait before the hit crime fighting TV drama series "Marvel's Agents of S.H.I.E.L.D." returns for the second half of its Season 2, fans are still hankering for more information on what to expect when it hits the small screen.

Cast member Clark Gregg, who plays the fearless leader of the organization, Agent Phil Coulson, recently sat shared his thoughts about the new elements of the show including the introduction of Inhumans as well as its progress towards a "darker tone."

"Inhumans are a really important part of that for me. I'm really excited to see how they use that part of it on our show. It's one of the things that's fun about being on this show. When you understand what it is, you see Winter Solider and it's "Agents of Nothing." Right when you think you know what that is, there's the attack at the end of the season and he can't stop carving [symbols]. It keeps adding new elements to it," the actor told IGN.

"That said, we're at nine o'clock, with a darker tone -- less ICERS, more bullets. I think it's finding its way to be more and more; its own central self that can withstand having things brought into it," Gregg went on to reveal.

Meanwhile, a full synopsis for the upcoming episode titled "Aftershocks" was posted in the Futon Critic where it reads:

"After discovering an alien city with ties to his resurrection, Coulson and his team destroyed it before the forces of Hydra could claim its secrets, eliminating the villainous Whitehall (Reed Diamond) in the process."

"But new threats to the world have arisen, including Skye's father, Cal (Kyle McLachlan), who now seeks retribution against Coulson for stealing his revenge against Whitehall; a disturbing alliance between former S.H.I.E.L.D. agent Ward (Brett Dalton) and Agent 33; the enigmatic Raina (Ruth Negga), who struggles with her transformation into something inhuman by the alien Obelisk and seeks vengeance; and Skye (Chloe Bennet), who developed mysterious new powers from the Obelisk but whose lack of experience with her new abilities may threaten the safety of those she loves."