Warning: The following contains spoilers for the Season 1 finale of Netflix's Russian Doll.

The Groundhog Day time loop isn't a particularly new concept, but Netflix's Russian Doll adds a unique spin to the story that makes it a truly worthwhile experience. The series, which star Natasha Lyonne co-created with Amy Poehler and Leslye Headland, is a darkly humorous and poignant tale about a woman's psychological struggles manifesting in the form of a never-ending time loop. Again and again, Nadia (Lyonne) is forced to repeat her ill-fated 36th birthday, which ultimately ends with her death. But it's funny, I swear!

Lyonne, who based the series on personal experiences from her own life, tells a surreal story grounded in existential questions of loneliness and happiness. As the narrative unravels, so does Nadia, who finally starts to unpack the trauma that has remained with her through adulthood and left her almost stuck in life. It's an affecting story that ends on a bittersweet, almost uplifting note as she makes a new friend who has also been struggling with personal demons in his own time loop.

Nadia and Alan (Charlie Barnett) realize at the end of the first season that their failure to help each other on the same night is what trapped them in their respective timelines. In order to break free of the loop, Nadia prevents Alan from killing himself, and Alan saves her from being struck by a cab. The two quickly befriend each other in both timelines, and the season wraps with the pair joining a parade of eccentrics led by Horse (Brendan Sexton III) as they merrily march through the streets, suggesting that the unlikely friends finally achieved a semblance of happiness with each other.

According to Headland, that hopeful ending wasn't so much intentional as it was simply the best choice for the show.

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"I don't think we went in feeling one way or the other in terms of a positive or negative ending. It was just really important to Natasha [Lyonne] and to Amy [Poehler] that it feel like a satisfying narrative that had explored all of these different emotional and spiritual and existential ideas," Headland told TV Guide. "So for us, it was about having a complete ending that felt right and I think for whatever reason, that story merited a bittersweet or positive one. We wanted to feel like it was worth sitting through four hours."

Reaching a worthwhile conclusion took a real effort from the show's creative team, who shuffled through multiple endings before landing on the one we see in the final cut.

"Working on this show was like solving a math problem," explained writer Jocelyn Bioh, who made her TV writing debut with Russian Doll. "We were trying to figure it out through and through and through. I don't even know if I knew the real ending until close to when they were filming it. That's how much we were working on it."

Russian Doll is now available to stream on Netflix.

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Amy Poehler, <em>Parks and Recreation</em>Amy Poehler, Parks and Recreation