For All Mankind Just Pulled Off a Wild Twist Almost No Other Show Could Match

The greatest sci-fi show is also a great spy drama.

Ranger 1 in 'For All Mankind.'
For All Mankind

Although For All Mankind Season 4 has shifted much of the drama to the Happy Valley Base on Mars, the show still has a strong undercurrent of terrestrial intrigue. As Kelly Baldwin explores the Korolev Crater on the far side of the red planet, and her father Ed Baldwin and Dev Ayesa conspire to steal the Goldilocks asteroid, an even bigger twist unfolds on Earth.

At this stage in For All Mankind, now set in an alternate 2003, it’s becoming uncommon to see characters from previous seasons (outside of the cast members we’ve met). And so, the return of one familiar face in Episode 8, “Legacy,” was certainly a shock for longtime fans. And with the turn of this character, one plot point set up in Season 2 — 20 in the past within the show’s chronology — is finally coming to fruition.

Spoilers ahead for For All Mankind Season 4 Episode 8.

While a conspiracy starts to heat up on Mars, the biggest twist of Season 4 literally opens this episode with the revelation that Sergei Nikulov (Piotr Adamczyk) is still alive and living under an assumed name in Iowa where he’s working as a math teacher. We haven’t seen Sergei since the conclusion of Season 3 in 1995 when, after making a deal with the KGB, Sergei was set free. Before that, starting in Season 2 in 1983, Sergei collaborated with Margo Madison (Wrenn Schmidt) to make sure the historic handshake in space between the Apollo and Soyuz spacecraft was successful.

Sergei’s return in For All Mankind, explained

Sergei Nikulov is back in For All Mankind Season 4.


Since Season 2, Sergei has been a sympathetic if slightly untrustworthy figure. It’s never been his fault he’s controlled by the KGB. But everything Margo does in Season 3 — and her horrible status quo in Season 4 — is all out of a desire to protect Sergei. In a recent interview, Wrenn Schmidt told Inverse that Margo’s more global and cosmopolitan politics can be understood through the lens of her relationship with Sergei.

“I think in Season 3, Margo already was seeing the bigger picture,” Schmidt says. “She and Sergei are in these terrible positions of being dedicated to science, but also hamstrung by all of the politics and the military. If we could just be free to collaborate and to share the way that scientists always did up until the building of the atomic bomb, how much further could we go?”

In Season 2 and Season 3, we see that Margo and Sergei can’t bridge the gap entirely between politics and science. Schmidt thinks Margo’s “fallacy” is her belief that she’s “smart enough to control it” until she realizes “she’s being manipulated by him.”

Of course, on some level, Sergei and Margo do love each other. If you listen to any of the wonderful music for the show composed by Jeff Russo and Paul Docette, you already know the track “Margo and Sergie,” from Season 3, is one of the most tender and beautiful pieces of soundtrack music. It’s all bittersweet and tragic because even though Sergie was a space data spy for the KGB, it was something he did against his will.

So as Margo returns to the US in Season 4 to help with the asteroid capture program, Sergei popping back up is the kind of twist we should have all seen coming, but somehow didn’t. For All Mankind frequently asserts the very real notion that a handful of truly idealistic scientific minds can push history in one direction or another. So just as Aleida and NASA need Margo’s help, everybody also needs Sergei’s help.

Margo and Sergei’s big decision

Margo (Wrenn Schmidt) learns the horrible truth about the KGB.


But the biggest revelation in “Legacy,” happens at the end. Sergei and Margo finally reconnect, and Sergei makes it clear that the current head of Roscosmos, Irina Morozova (Svetlana Efremova), is a former KGB operative. In fact, she was his “handler” 20 years prior in Season 2, and certainly the person behind his torture in Season 3.

So if Margo stays with Roscosmos, she’s almost certainly doomed to a similar fate as Sergei, which is why he tells her, “You can’t go back there.” By the end of Episode 8, it seems like Samantha Massey’s conspiratorial tasks on Ranger 1 are going to be impossible. But in reality, the most challenging and dangerous game this season is perhaps being played on Earth. Because if Margo can’t go back to the USSR safely and she’s a traitor in the eyes of NASA, where can she go? Clearly, before the end of Season 4, one of the most important characters in the entire series will be changed forever. But right now, it’s not entirely clear what that fate looks like.

For All Mankind Season 4 streams on Apple TV+.

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