Zombie at 17 is a Canadian horror/thriller movie directed by Alexandre Carrière and released in 2018. The film stars Laurie Fortier as Kate, a single mother who lost her husband and elder daughter in a tragic accident, Celeste Desjardins as Tia, Kate's surviving teenage daughter who is dealing with the loss and her own ordeal, and Carson MacCormac as Flynn, a misfit teen who befriends Tia and helps her with her supernatural problem.
The movie starts with a prologue showing the hit-and-run that killed Tia's sister and traumatized her family. Then, the story jumps forward to the present day when Tia and her mother are still struggling with the aftermath of the tragedy. Tia is a popular student and cheerleader at her high school and has a loving boyfriend named Connor (played by Danny Roy), but she also has some unusual symptoms that she keeps hiding: she feels cold all the time, her skin is turning pale and cracked, and she craves raw meat.
One day, while researching her symptoms on the internet, Tia comes across Flynn, a boy who claims to be an expert in the occult and supernatural. Despite their initial awkwardness, Tia and Flynn become close and start exploring different theories about what might be causing Tia's affliction. They suspect a virus, a curse, or even alien abduction, but they cannot explain why Tia is still conscious and sentient, unlike the mindless zombies of popular culture.
Things get more complicated when one of Connor's friends, Jason (played by Keenan Lehmann), is found dead in the woods, apparently murdered. Tia knows that Jason and his gang are responsible for a lot of bullying and harassment at school, but she also knows that they have some connection to her condition. When Tia tries to confront Connor about it, he denies any involvement and tells her to drop it and stay out of trouble.
Meanwhile, Kate is doing her own investigation into what happened to her daughter and discovers that the only doctor who might have a clue about Tia's condition is a recluse who lives in the woods and has a shady reputation. Kate risks her own safety by seeking out the doctor, who is played by Robert Nolan, and bargaining with him to help Tia. The doctor agrees reluctantly and warns Kate that the cure might be worse than the disease.
As Tia's symptoms worsen and she starts to lose control over her actions and her hunger, she becomes increasingly isolated from her own friends and family. She also becomes a target for Jason and his gang, who suspect that she might be the one who tipped off the cops about their illegal activities. Tia knows that she cannot turn to the authorities without exposing herself and risking being killed or quarantined, so she relies on Flynn and her mother's help to find the cure before it's too late.
The climax of the movie takes place at a Halloween costume party, where Tia and Flynn suspect that Jason and his crew are planning to sabotage the event and cause chaos. Tia confronts them and tries to make a deal, but things go awry when the doctor's cure does not work as expected and Tia transforms into a full-fledged zombie. The final scenes of the movie show Tia and Flynn escaping from the party and driving away in Flynn's car, while Kate stays behind to distract the cops and buy them time. The movie ends with a cliffhanger, suggesting that Tia and Flynn's journey is not over yet.