
According to its creator, the Severance Season 2 ending was meant to make everyone feel the way it did with its shocking Mark S. twist.
The Season 2 finale saw Adam Scott's Mark S. using both his innie and outie personalities to work together and break out his thought-to-be-dead wife Gemma (played by Dichen Lachman) from the cold, corporate clutches of the mysterious megacorp, Lumon... but Mark and Gemma did not get the happy ending fans thought was possibly coming.
The Severance Creator Explains Season 2 Ending

Severance creator Dan Erickson explained the Season 2 ending, confirming fan suspicions about the show's mind-boggling finale.
The show's Season 2 finale came to a close with Adam Scott's Mark S. turning back into the halls of Lumon after he got his outie's wife, Gemma, out from her severed bounds on the company's terrifying Testing Floor.
This was a shock to fans, as it seemed like the series had been leading to Mark reuniting with his wife, especially after he discovered she was alive in Season 1's own massive finale cliff-hanger.
However, that did not happen. Instead, Mark's innie chose to stay on the Severed Floor with Britt Lower's Helly R., an act that fans assumed to be Mark's innie taking control of his life for the first time instead of bending to his outie's every beck and call (read a detailed Severance Season 2 finale break down here).
It turns out that is exactly how the series' creators wanted fans to take the show's shocking Season 2 ending.
In a conversation with The Hollywood Reporter, Erickson said the goal of the Season 2 finale was to "get Mark to the point where...he has come to value himself as a person and value his life" apart from his outie:
"And so, what if this season you try to get Mark to the point where, as he’s standing at that door about to go out and finally give his outie what he’s always wanted—his wife back—he doesn’t do it because by this point, he has come to value himself as a person and value his life and the lives of his friends and work family as much or more than the outies? That just seemed like a really interesting place, a challenge to try to get his character to that point."
To this point, Mark's innie had only ever been "beholden to his outie" and saw his "outie as more important than himself:"
“But it just occurred to me because at the very beginning… I mean, literally the first thing that we see Innie Mark do [in season two] is come out of the elevator and run to go find Ms. Casey. At that point in the story, he still feels totally beholden to his outie and that life, and I think still on some level, sees his outie as more important than himself."
So, this turn back into the hallway at the end of Season 2 was Mark grabbing hold of the reins of his life, showing that he, too, has autonomy and is not just an extension of his outie self.
According to Erickson, this ending twist was not something he had planned from the beginning but "came about in the writer’s room:"
"I always knew that I wanted this season to end with Mark freeing Gemma. What I didn’t necessarily know was that he was not going to follow her. That was something that came about in the writer’s room. There are certain things that we are leading to story-wise that I knew we were going to do, and this ended up working really well for that."
Severance director and fellow creative force on the series Ben Stiller corroborated this sentiment during an interview with Variety, positing that this season finale sees Mark's innie "living his own life:"
"That was always a very clear endpoint for this season. It always felt to me, even from the first season, that this is the track the story was going to go down. That the emotional connection that Mark and Helly develop in Season 1 is going to become a very real thing, and it’s directly at odds with Mark and Gemma’s relationship on the outside. It makes total sense—Innie Mark is living his own life."
What Is Next in the World of Severance?

With Severance Season 3 officially announced, Mark S.'s story seems to be just getting started—especially from the point of view of his at-work innie.
The Season 2 finale leads fans to believe a third season will focus on putting Mark's two consciousnesses at odds, as one seeks to bring Lumon down from the outside and the other from within. This could get particularly prickly as Mark's ongoing reintegration process continues to take hold.
Season 2 saw Adam Scott's Lumon employee embarking on a journey to fuze his two severed personalities together, but the procedure has not quite been 100% completed.
However, fans have gotten glimpses of it working, as Innie Mark was seen in brief stints flashing into the outie world and Outie Mark doing the same with the innie world.
The upcoming Season 3, which has been teased as coming "sooner" than Season 2 did, looks like it will largely focus on Innie Mark within the halls of Lumon, leading something of an innie revolt against the show's Machiavellian megacorp.
This would be a herculean task on a good day, but if Mark keeps flashing between his innie and outie as the reintegration process continues in his severed brain, this could amplify the difficulty of the task at hand tenfold as both versions of the character attempt to forward their own agendas.
All fans know is that Innie Mark put his foot down to close Season 2. It is just a matter of how Outie Mark will react when he figures out what happened.