After her wedding, Erin Hasegawa heads to her old sorority for fun, only to find something terrifying hunting her and her friends. Something unknown, remorseless and seemingly unstoppable as they struggle to survive and see who will be left.
- Action Survivor: Erin, Emma and Dani have been in enough to avert this, but Erin's other muggle friends from her old dormitory qualify as this by the end. All of the named characters (save maybe Dana) survive intact by the end despite being hopelessly out of their game.
- A Day in the Limelight: For Erin Hasaegawa, focusing on her and her friends from college. Hardestadt is relegated to the background.
- Domestic Abuser: Erin's ex-boyfriend Ian is described as being emotionally controlling to Erin when they dated, even sleeping with her friend on Valentine's Day, and gaslighting her. Erin later looks back on this without fondness.
- Final Girl: Averted as all of the main characters are women, and Everybody Lives.
- Good Girls Avoid Abortion: Discussed. Erin ended up pregnant during her terrible relationship with her college boyfriend Ian Saxon and decided to terminate it. Discussed in Erin's POV as she didn't do it for revenge or spite, but simply wasn't ready to have a child, and has no more anxiety over it than she would any other medical procedure.
- Happily Married: Both Hardestadt with Erin and Emma with Dani.
- Malevolent Masked Men: One of the few times the entity is seen directly, it's wearing a mask in the form of Erin's ex-boyfriend.
- Nothing Is Scarier: Nothing is revealed about the strange entity in the end, who Dana was or what her role in it was, or why Erin and the others saw all the other party-guests in strange pods.
- Psychopathic Man Child: Erin describes the killer as this, given the juvenile texts he sends to taunt her.
- Shout-Out: The setting and the way the plot is framed is an homage to the original When a Stranger Calls: just before the strange happenings in the dorm start happening, Erin starts receiving perverted phone calls that turn out to be coming inside the dorm.
- The Spook: Several characters. Dana vanishes by the end and nobody quite knows who she was or if she had a part in the plot, and the strange entity's intentions and fate are never quite revealed. Even the one woman who seemingly died never has any clarity shed on her fate.
- Your Cheating Heart: Alicia had sex with Erin's boyfriend in college, on Valetine's Day of all times. In the present Alicia wants Erin's forgiveness, which Erin ultimately extends.