Here is the official synopsis:
"The Blitzkrieg Button" - Peggy may be in more trouble than usual when fugitive Howard Stark suddenly returns for mysterious reasons. And Chief Dooley chases a new clue all the way to Europe that threatens to destroy Peggy's future at the SSR, on "Marvel's Agent Carter," Tuesday, January 27 (9:00-10:00 p.m., ET) on the ABC Television Network.
"Marvel's Agent Carter" stars Hayley Atwell as Agent Peggy Carter, James D'Arcy as Edwin Jarvis, Chad Michael Murray as Agent Jack Thompson, Enver Gjokaj as Agent Daniel Sousa and Shea Whigham as Chief Roger Dooley.
Guest starring are Lyndsy Fonseca as Angie Martinelli, Alexander Carroll as Agent Yauch, Dominic Cooper as Howard Stark, Bridget Regan as Dottie Underwood, Benita Robledo as Carol, Meagan Holder as Vera, Joanna Strepp as Gloria, John Bishop as Frank, Tim Dezarn as George, Billy Malone as "large" smuggler, Jeremy Timmins as "larger" smuggler, Chad Danshaw as thug, Jack Conley as Colonel Mueller, Kevin Cotteleer as Alex Doobin, Gregory Sporleder as Otto Mink, Jim Palmer as goon, Tim Garris as hoodlum, Stan Lee as man (next to Howard Stark) and Sarah Schreiber as Lorraine.
"The Blitzkrieg Button" was written by Brant Englestein and directed by Stephen Cragg.