TV Guide debuted the following image of Atwell as Agent Peggy Carter where we also see the Howling Commandos from Captain America: The First Avenger with Kenneth Choi and Neal McDonough as Jim Morita and Dum Dum Dugan, respectively.
It's stated the trio will be featured in a 1940s flashback sequence in the Season 2 premiere episode.
"Coulson is a big student of history and wants to return to those old ideals of Agent Carter's time," executive producer Jed Whedon said. "He's, like, 'Let's be the S.H.I.E.L.D. we were meant to be!' He wants to do the job right this time."
"Marvel's Agents of S.H.I.E.L.D." Season 2 debuts Tuesday, September 23 at 9pm ET on ABC, with "Agent Carter" premiering in 2015.