Carter finally gets a chance to prove herself as she is sent on a mission in Russia with Agent Thompson and the Howling Commandos. Meanwhile, Agent Sousa makes an important discovery.
When Demidov's typewriter sends a message which is encrypted. Carter figures out what it is, a location which they think is a meeting with Stark in Russia. So Dooley sends Thompson to check it out but Carter wants to go. But they won't let her but when she says she can get the Howling Commandos, they let her go. When they get there they discover Stark is not there and something is going on. Dooley talks to someone about Stark who makes him question if Stark is really a traitor. And Sousa through a chance encounter with Carter learns she's the woman they're looking for.
- Russia, 1937
A young blonde girl wakes up handcuffed to her bed, along with dozens of other girls. The girls attend a class, watching "Snow White" to practice their English. They fight hand-to-hand combat and are trained to kill each other.
New York, 1946
Peggy's neighbor Dottie begins her day with rigorous sit-ups. Then she puts on a giggly face and has breakfast with Peggy. Dottie "accidentally" knocks over Peggy's purse and swipes her keys.
Jarvis finds Peggy at a newsstand and tries again to apologize. Peggy is still angry at Howard Stark for using her to get Captain America's blood. Jarvis asks if she honestly thinks her male colleagues will ever give her a chance.
When Peggy arrives at SSR, it's a beehive of activity following the magic typewriter spitting out a message. A code breaker is having no luck with it, but Peggy decodes it quickly and finds map coordinates and a message setting a time to exchange a purchase. It references Leviathan and a havoc reaker. The message ends with saying the payment is for Howard Stark.
Peggy has to argue with Chief Dooley to get to go on the mission to Russia, where she spent three years during the war. Agent Thompson argues against her going, and Dooley is about to agree. Peggy suggests she can get the 107th regiment, who know the terrain better than anyone, and Dooley agrees to let her go if she can. She does with one phone call.
Peggy has to use the men's locker room because there's no place for women to change into tactical gear. When Agent Sousa comes in, Thompson tricks him into walking in on Carter changing. He takes note of two scars on her shoulder.
On the plane over Poland, Thompson is visibly nervous before his first real parachute jump. On the ground, they meet up with Happy Sam Sawyer, Pinky Pinkerton, Junior Juniper and Dum Dum Dugan, the Howling Commandos. The SSR agents are in awe that they fought alongside Captain America, and Dugan points out Peggy fought with him longer.
In the trucks on the way, Peggy shares the bourbon Dugan requested. Peggy thinks the message about Stark is just Leviathan trying to lure them in for a trap.
Back at the SSR office, Sousa pulls Peggy's medical records and sees that her shoulder scars are gunshot wounds. He compares them to the photos from the club of his mystery blonde and finds the same scars.
Gathered around the campfire, Peggy gets a reluctant Thompson to tell the story of why he was awarded the Navy Cross. He fell asleep on night watch in Japan and found six Japanese sneaking into his camp. He shot them all before any of his men even woke up.
Back in New York, Agent Dooley meets with a reporter to learn more about the Battle of Finau, in which 247 Russians died. He says Stark was there for the clean-up. He picked a fight with General McGuinness and lost badly, but McGuinness resigned a week later. (He died a few months ago.) A week after that, Stark cut all ties with the army and walked away from a huge contract. He suggests SSR doesn't have the full story about Howard Stark.
The next morning in Russia, Thompson listens to Peggy's suggestion about how to go into the meeting spot. It's the old school where the girls were trained to pass for Americans. They see handcuffs on beds in the next room and find a young girl crying. Dugan approaches her gently and the second he looks away sticks a knife in his chest. She grabs Dugan's gun, shoots Juniper and ninjas around the and out a secret passage. Peggy stops Dugan from lobbying a grenade after her (his vest stopped the knife). Juniper is dead.
Peggy gives orders, telling Dugan they can't leave without finding out who's setting up Stark.
Dooley goes to Jarvis and asks about McGuinness. Jarvis says he doesn't know anything. Dooley assures him he just wants the truth and leaves a number for Stark to reach him.
Back in Russia, they find men in a basement jail.
Back in New York, Dottie uses Peggy's key to go into her room and search the place. She finds photos of Stark's inventions in Peggy's hidden jewelry box and takes one. She sits down at Peggy's vanity and pokes through her things then replaces the string on Peggy's lock to hide that she was there.
In Russia, the men in the cell explain that Leviathan acquired some plans on the black market and are using them to build what's in them. One man is a scientist named Nikolai and the other is his doctor, helping him keep it together. They have Stark's plans but say they've never seen him and the plans are stolen.
When Leviathan arrives, the team releases the captives and runs for it. They get pinned in the boiler room, where the young girl shoots Agent Li in the head. Nikolai grabs Happy and offers him up as a hostage. His doctor tries to talk him down and Peggy gives Nikolai until the count of three to release Happy. The doctor kills Nikolai on "one."
Peggy takes control in the firefight as Thompson cowers. Finally Dugan busts through a wall, providing them with an escape route. When Thompson is still paralyzed with fear, Peggy runs through gunfire to grab him and get him moving. She insists on staying behind to keep taking out Russians as everyone else makes it to safety. She runs to the truck in a hail of gunfire, loving every minute of it.
Later, Dugan says his good-byes to Peggy. She declines his offer to join him in the field. The doctor agrees to come back to New York to join the SSR in stopping Leviathan.
On the plane back, Thompson grudgingly admits that Peggy saved a lot of lives, including him. She tries to make him feel better by saying everybody freezes sometimes. He admits the soldiers he killed in his camp in Japan were carrying a white flag -- but he didn't realize it until it was too late. He buried the flag before anyone else saw it. "Everybody thinks that I'm this guy that I never was and every day it gets harder and harder to live with it," he says.
Back at the Griffith, Dottie gets ready for bed, handcuffing herself to the head board.
Back at SSR, Thompson gives Peggy credit for bringing Doctor Ivchenko back. Thompson still thinks Leviathan might have gotten the plans from Stark himself.
As the agents head home for the night, Thompson invites Peggy to join them at the bar. Sousa stays behind, unsure of what to make of Peggy as his mystery blonde.