Birthdays are often a time for celebration, but it isn’t all parties and presents when emotional baggage is the gate-crashing guest. In the case of Nadia (Natasha Lyonne) on Russian Doll and Happy Death Day 2U’s Tree (Jessica Rothe), they both have to contend with mother issues dredged up by this particular milestone. Deep-rooted parental trauma is pretty standard storytelling fare, however, Nadia and Tree also share a time loop predicament, as they are forced to relive the same day over and over. Death stalks them at every corner whether it is a baby mask-wearing killer or a set of stairs that are seemingly impossible to navigate without dying.

A day that keeps repeating sets up a huge challenge for a protagonist to overcome; in the case of recent movies such as Source Code and Edge of Tomorrow, this loop is tied to a larger mission to save lives/and or the world. In Groundhog Day — the defining time loop movie — personal growth is the key to hitting stop on the reset button. Both Russian Doll and Happy Death Day 2U fall more into the Groundhog Day column, but there is a larger story to be told that goes beyond the trials and tribulations faced by Bill Murray as cynical weatherman Phil Connors.

Detailed spoilers for Russian Doll and Happy Death Day 2U ahead.

Absent mothers provide the foundation for the trauma at the heart of both Nadia and Tree’s birthday conflict. In Happy Death Day 2U, Tree shares a birthday with her deceased mom, doubling down on the heartache of this particular date. Meanwhile, Russian Doll's Nadia is celebrating hitting 36 at the party thrown by her friend Maxine (Greta Lee). It's a seemingly innocuous age, but her mom died before making it this far. “This was always going to be a tough birthday,” says Ruth (Elizabeth Ashley), Nadia’s aunt and surrogate parent, in Episode 1, just after Nadia has experienced her first reboot of sorts.

Nadia complains about feeling “profoundly empty,” but she is also pretty sure she is in the middle of drug-induced déjà vu. She will quickly learn this is not the case. Existential dread permeates every corner of Russian Doll as Nadia tries to claim her mother is not at the root of this state of ennui; no one wants to be a psychological cliché. But sometimes the obvious answer is the correct one.

This isn’t simply a case of vanquishing past demons to beat this time loop, or even going on a journey of self-improvement. Guilt buried deep within Nadia since her tumultuous childhood has unquestionably shaped who she is as an adult. Penetrating Nadia’s well-maintained defense barriers is a mission in and of itself. She is unashamedly honest, which doesn’t stop her from having close friendships, but this DGAF attitude also puts distance between her and her nearest and dearest.

Six months before her birthday she ended her most meaningful romantic relationship with John (Yul Vazquez) and she still doesn’t want to commit to meeting his daughter, despite her own best efforts. The latter is rooted in her childhood trauma, but Nadia uses the repeated death cycle as an excuse for postponing the breakfast she suggested — in fact, her most bloody and brutal death takes place in front of John’s daughter at the end of the penultimate episode.

You’d think living with a therapist would rub off on Nadia, but it has probably made her more resistant to opening up. Ruth imparts important wisdom by reinforcing the notion that we are the sum of all our parts, telling Nadia in Episode 5, “Right now, I am looking at you as you are today, while also looking at you as that peculiar little girl I knew.” Good and bad can co-exist, as can "yes" and "no," and life and death.

This is also the episode in which Nadia realizes — after Ruth shoots and kills her — that each time she dies there is a version of Ruth grieving for her (except in the versions where Ruth also dies in the gas explosion). The point is, there are consequences beyond Nadia’s experiences of the timeline resetting. Often in time loop situations, it is about improving the self — while sometimes saving the world — but in Russian Doll, it expands beyond both of these things. The people around her are not just bystanders in this adventure.

The self is still important, but Nadia’s journey — in which she confronts her traumatic past — is not one she undertakes alone, no matter how hard she pushes people away. The introduction of Alan (Charlie Barnett) at the end of Episode 3 instantly elevates Russian Doll from a fun and sardonic spin on this narrative device to something that cuts to the core of the messiness of existence. It is not a one-player journey; you can attempt it by yourself, but you will end up back at the same point trying to complete the same level, over and over. Nadia claims she never sticks her neck out for anyone, but we see her concern for those she loves and strangers such as Horse (Brendan Sexton III).

“Life is like a box of timelines,” Nadia jokes in the Russian Doll season finale, an experience Tree is more than familiar with in Happy Death Day 2U. Like Nadia, Tree is forthright with her opinions and is prone to putting up emotional barriers. But unlike Nadia, Tree finds out exactly what is causing her time loop predicament.

It is not, as Tree believed, the universe trying to impart an important message, instead, it is Carter’s (Israel Broussard) roommate Ryan (Phi Vu) who is responsible for the whole multiverse mess. His science thesis project is the device that inadvertently set Tree’s birthday to repeat. In the sequel, Tree ends up in a dimension in which her birthday and baby mask killer are still the main features. This timeline looks like the one she just came from but there are some big changes: Carter is dating Tree’s frenemy Danielle (Rachel Matthews), her roommate Lori (Ruby Modine) doesn’t want to kill her, and her mother is not dead.

If Happy Death Day was Scream meets Groundhog Day, then this sequel is taking lessons from Back to the Future II, a movie franchise Tree admits she has never seen. Both Russian Doll and Happy Death Day 2U are genre-bending, mixing elements of sci-fi, comedy, horror, drama and even romance. The beauty of a time loop set-up is it is rooted in science-fiction, but can dart off in any number of other directions. 

Tree is faced with a new existential crisis after finding out what she endured in the first movie wasn’t a cosmic lesson to help her face her mom’s death, but instead part of a science experiment gone awry. Nevertheless, even though her role at the heart of this journey was pure coincidence, she shouldn’t dismiss the cathartic experience because it did make things better in her timeline. New bonds have been formed, she confronted her grief and her roommate wasn't the one responsible for killing her this time around. 

The real curveball is that her mother is alive in this dimension, but this version of their relationship isn’t real. Tree finds photos of moments that didn’t happen in her world and her mom talks about their last birthday together, which this Tree has no recollection of. These are not her memories; this is a version of her life that is not hers.

The past has its grip on Tree as she contemplates staying in this dimension rather than returning to where she came from. Battling yet another killer is scary, but confronting losing her mother again is a nightmare she doesn't want to relive.

If in the first movie Tree let herself be vulnerable for the first time since her mother died, Happy Death Day 2U doubles down on dealing with loss and grief. However, now it isn’t just Carter helping her with this time loop and murderer predicament; she has a whole team.

Time resetting gives a character numerous attempts to get something right. This is part of the appeal of this plot device, as a variety of options are presented, often without lasting consequences because the day just begins again. The results are often hilarious and both Russian Doll and Happy Death Day 2U have a strong comedy thread running throughout — and yet there is a foundation of pain underneath the repeated slapstick deaths.

"We're all broken on the inside, let's do it together," said Russian Doll star/co-creator Natasha Lyonne on Late Night with Seth Meyers recently while promoting the Netflix show, which is something both Nadia and Tree learn across their never-ending birthday adventures. 

Second chances aren’t always easy to come by, and neither is a clean slate, but these tales offer up a chance for both. In this age of anxiety, as a result of a tumultuous and uncertain political climate, time loop narratives can feel like a calming presence because there is the chance to get it right. Birthdays are a good way of taking stock of the last year, but hopefully, next time Tree and Nadia will get to enjoy their cake and chicken in relative peace — or, at least, with fewer baby masks and less stair-related peril.