Leviathan is about to enact their murderous plan, and it's up to Peggy and the SSR to stop them. And an ally has returned to help them catch the culprits: Howard Stark.
Tropes:
- Brick Joke: After a long string of incorrect guesses, Howard finally remembers that "Dottie" was calling herself "Ida" during their weekend together... well after that information was worth anything.
- But for Me, It Was Tuesday: It takes Stark half the episode to figure out which of the women he'd taken to his secret vaults was the one who kidnapped him.
- Call-Back: Peggy has to talk to a person flying a plane over the radio. This time, it was a happier ending.
- Call-Forward: 70 years in the future, Trish Walker copies Souza's method of approaching someone with a Compelling Voice without being controlled.
- Destination Defenestration: At the end of their fight, Peggy kicks Dottie out of the window of the hangar's radio room.
- Due to the Dead: Peggy goes to the Brooklyn Bridge and empties the last vial of Steve's blood into the water, both letting Steve go and bringing a small part of him back to his home.
- Futureshadowing: The final scene shows where the future HYDRA will get its brainwashing "Faustus method" from.
- Fake Ultimate Hero: While everyone in the SSR knows who really saved the day, the government decides to award all the credit to Agent Thompson, who, while the senior-most agent present, contributed the least to stopping Fennhoff's plan.
- General Ripper: The late General McGinnis. He ordered a raid on Stark's lab and stole Midnight Oil even though he knew it wasn't ready to be used on human soldiers.
- Gone Horribly Wrong: Midnight Oil was created by Stark to keep soldiers awake for days without needing sleep. Once created, staying awake became the least of patients' problems. Several tanks were stolen during a raid of one of Stark's labs, and then intentionally released... on the allied Russians, which led to the massacre at Finow.
- Hate Plague: Item 17 / Midnight Oil. Sousa accidentally gets a facefull of some left in a canister, and tries to kill Thompson before being held down long enough to come back to his senses. It eventually turns out that Dr. Fennhoff's plan is to drop a payload full of the gas into Times Square on the anniversary celebration of V-E Day, resulting in the slaughter of much of the population of New York.
- Idiot Ball: Seriously, who thought putting Fennhoff in a cell with Arnim Zola was a good idea?
- Ignored Epiphany: In episode 5, Jack Thompson admitted being ashamed of being rewarded for heroics he didn't perform, and starts recognizing Peggy's achievements more. At the end of this episode, he's being lavishly praised for his supposed heroics on this case, considers telling them it was really Peggy's heroics... and says nothing, letting himself still take all the credit. Sousa is not impressed by this.
- Killed Offscreen: Double-subverted. Dottie is pulled over by a policeman, and when the cop realizes she's wanted Dottie holds him at gunpoint. Cut to the next scene. Then later it turns out the cop wasn't killed, but hypnotized by Fennhoff for the next step of his plan. Then Jarvis catches up to the rogue police car, and finds the cop now actually dead.
- Lack of Empathy: Nothing better illustrates this of Fennhoff than when he's hypnotizing Howard Stark. Fenhoff can tell that Stark, the object of Fenhoff's hatred and revenge, does feel genuine, sincere remorse over what happened at Finow. It doesn't stop Fennhoff from carrying out his plan of hypnotizing Stark into committing an even worse atrocity in New York.
- My Greatest Failure: It turns out that Stark's greatest regret is not finding Steve Rogers after the Valkyrie went down in the Arctic. Fennhoff hypnotizes him into believing he's flying to Steve's location when he's really flying straight to Times Square in a plane laden with Midnight Oil gas cans.
- Never Found the Body: Peggy knocks Dottie out a window onto the wing of a plane in what appears to be a Disney Villain Death. But after she's finished talking Stark down and heads back down to the hangar, Dottie's body is missing, with blood spatters indicating that she fled the scene.
- O.O.C. Is Serious Business: Howard Stark, a man with a notoriously unflappable and arrogant personality who primarily cares about himself, is brought to tears when Fennhoff reveals what he suffered at Midnight Oil's hands, and begs the doctor to not use the gas to kill innocent civilians.
- Out-Gambitted:
- Stark's plan to capture Leviathan is for the SSR to hold a press conference declaring his innocence in hopes of drawing the bad guys out. Sure enough, an assassination attempt occurs, but it turns out Leviathan wasn't even trying to kill him, instead luring him into a police car to capture him.
- Fennhoff himself thinks he's outwitted both Thompson and Sousa, by knocking out the first agent and then compelling Sousa to stop holding him at gunpoint and kill Thompson instead. At first it seems to be working, only for Sousa to promptly knock Fennhoff down; he hadn't even heard the doctor's speech thanks to earplugs.
- Rule of Three: Shocked and horrified at how the S.S.R. had poorly handled his inventions, Howard properly adjusts three of them.Stark: This is photosensitive! It needs to be kept in the dark! This needs to be kept cold! This [picks it up. flips it over. puts it down] [Beat] is fine now.
- Sequel Hook: The season finale ends with several hints for the happenings in Season 2.
- Peggy is now respected by her coworkers, and may or may not go on a date with Sousa. Thompson has been promoted to Deputy Director.
- Angie is moving into Stark's vacant mansion with Peggy, and Jarvis as a regular visitor.
- Dottie has escaped and no one knows where she's gone.
- Dr. Fennhoff is imprisoned and forcefully kept from speaking. But his prison roommate is another talented supervillain, Dr. Arnim Zola, and we know what he ends up doing.
- The Sleepless: Item 17 / Midnight Oil was supposed to enable people to function for days without sleep. Instead, it triggers an amplified version of the sort of mental breakdowns caused by prolonged lack of sleep.
- Villain Team-Up: Zola proposes a way of collaboration to Fennhoff, implicitly suggesting that he give him his hypnosis formula by writing it down.
- Wham Shot: Dr. Arnim Zola, former minion to the Red Skull and future founder of the new HYDRA, showing up in Dr. Fennhoff's prison cell.
- Woman Scorned: Every time that Stark fails to correctly remember the identity that Dottie was using when she slept with him, she hits him.
- You Killed My Father: Fennhoff's brother died horrifically at Finow, leading him to seek revenge against Stark for inventing Midnight Oil.
