Everyone who pays attention to the Marvel Cinematic Universe knows that Peggy Carter was a founding member of S.H.I.E.L.D.. That was the big reveal at the end of the Agent Carter short, and Cap saw her photo on the wall of the abandoned S.H.I.E.L.D. facility in Captain America: The Winter Soldier.
Now Peggy Carter, Jim Morita, and Dum Dum Dugan will appear in the season premiere of Agents of S.H.I.E.L.D. in a flashback scene that shows an early S.H.I.E.L.D. mission. Marvel released the above image of the scene to TV.com.