In the first trailer for Season 2 of "Agents of S.H.I.E.L.D.," it was revealed that the team has now turned into 'ghosts' who will remain in the shadows to protect the innocent. The show has leaned more into the espionage angle, and there will be distrust, secrets and gadgets all designed to thrill viewers.

It shows some new footage of Skye interacting with an imprisoned Ward and May fighting Marvel's Absorbing Man, known as Carl "Crusher" Creel. Coulson, in voiceover, stresses the truth about HYDRA's advantage over S.H.I.E.L.D.

ScreenCrush reports that in the forthcoming season, several stars will also be making guest appearances. Henry Simmons will appear as a S.H.I.E.L.D. agent named Alphonso "Mac" Mackenzie. Nick Blood will play the role of Lance Hunter, a mercenary and veteran agent of S.H.I.E.L.D., Isabelle Hartley will be played by Lucy Lawless.

There will also be a royal right hand man by the name of Bakshi who will be portrayed by actor Simon Kassianides. Daniel Whitehall, aka Kraken, a HYDRA agent, will be portrayed by Reed Diamond. Skye's father will make an appearance as well, played by Kyle MacLachlan. Glenn Talbot, played by Adrian Pasdar, will also return and Maria Hill, played by Cobie Smulders, will also make a re-appearance.

Adrienne Palicki will be appearing in the fifth episode of "Agents of S.H.I.E.L.D." in Season 2. With the confirmation, Adrienne Palicki will be joining the numerous stars that have already done guest appearances in the "Agents of S.H.I.E.L.D." She will portray the role of Bobbie Morse, the superspy codenamed Mockingbird.

While it was announced that Palicki will only be a guest, it is possible that Mockingbird will make an appearance now and again throughout the season, which is due to premiere on Sept. 23 at 9 p.m. ET, according to TVLine.