In 1946 S.S.R. Agent Peggy Carter struggles with her diminished position in the wake of Captain America's disappearance -- until an embattled Howard Stark asks her to stop a deadly weapon he invented, and clear his name.

Peggy and Jarvis attempt to locate and recover a truck full of Stark's weapons -- all while staying one step ahead of her fellow S.S.R. agents.

Mr. Jarvis finds himself being interrogated by the S.S.R. after evidence connecting him to a major crime is uncovered. Meanwhile, Peggy discovers a cache of more of Stark's dangerous inventions.

Howard shows up looking for information on which of his dangerous inventions have been recovered, putting Peggy in a difficult situation when she must steal one out from under the S.S.R. Agent Dooley travels to Germany, where a prisoner of war reveals a key piece of information.

Doubting her commitment to Howard Stark, Peggy calls upon her Howling Commandos squadron when the S.S.R. consents to send her on a covert mission to Russia.

Agent Carter attempts to track the whereabouts of a powerful Russian agent. But after Agent Souza learns the truth about her, Peggy finds herself targeted by her own agency.

Jarvis attempts to intervene when Peggy is taken into custody by the S.S.R., who are convinced she is an enemy of the state. Chief Dooley finds himself under the spell of Dr. Ivchenko, who intends to steal something from the building.

After Ivchenko and "Dottie" successfully tests a chemical weapon, Howard Stark makes a surprise return to help the S.S.R. catch them and save the city -- by using himself as bait.