NOTE: This spoiler was submitted by Geoff
The movie opens with a group of friends at a party drinking. They start talking about an app that predicts when you are supposed to die called Countdown. One by one they start sharing the date they were assigned but one of the friends named Courtney (Anne Winters) gets an assigned death time of later that night. After the party, Courtney’s boyfriend Evanis drunk and attempting to drive her home but because of the countdown timer she’s wary to let him drive her home and insists that they walk. Evan gets mad and drives off on Courtney leaving her to walk home alone. She then gets a notification saying that she violated the user agreement of the countdown app. While she is walking we see a cloaked figure following closely behind her but then the figure peels off and gets into a nearby car and drives off. Courtney runs into her house and locks the door and looks outside. She then goes into the bathroom and fills a glass of water, and checks the shower as the countdown app goes off. She drops the glass and then gets dragged into the air vertically and dropped so that her neck breaks across the bathtub. The scene shifts to where an SUV crashed into the woods and we see the driver was Evan, and in the passenger seat where Courtney would have been there is a tree branch that has gone through the truck and into the seat, so Courtney would have died either way. The credits start.
At the hospital, Evan meets Quinn, the main character (Elizabeth Hail) who is a nurse at the hospital. She tries to comfort Evan who is due for surgery and on crutches and in a foot cast. Evan laments the death of Courtney and is conscious of his impending mortality since the countdown app has him dying during surgery.
We meet Quinn’s coworkers who work under head Nurse Amy (Tichina Arnold) and a few of them start downloading the Countdown app and laughing about the time they have. Suddenly a couple come into the hospital room with the girlfriend apparently having overdosed so the staff resuscitates her with a dose of narcan.
We go back to Evan, who is wandering around an under construction area of the hospital to avoid the surgery and we see he gets the user agreement violation. He sees a hooded figure behind him in the hallway mirror and when he looks back it’s gone. The lights start to flicker and he ends up escaping to a stairwell. He sees an apparition of Courtney on the steps and calls her name, but when she turns around her face is decayed and her eyes are yellow. The camera cuts to the bottom of the stairwell and we see Evan fall along with his phone.
Quinn is leaving work for the day and downloads the countdown app and sees she has three days to live but shrugs it off. She stops by her fathers house to get information for her I-9 (work forms) and the tv is on. She hears a noise in the closet and opens it to find her younger sister Jordan (Talitha Bateman). She slides some clothes over to see a bare chested boy and she scolds her sister. We see that the relationship between the sisters is a bit tense, as the younger sister resents that Quinn doesn’t spend a lot of time with her and their father since her mother died. At work the next day, Quinn finds out Evan died and she goes down to where his body is stored to find his phone. She sees the photo of Courtney and him on his home screen and decides to research. Back upstairs, Quinn cancels plans to hang out with her dad and sister and gets the notification that she violated her user agreement. As she walks through the halls a dark figure is in the background of one of the rooms, but when she walks backwards the figure is gone. Then Quinn’s supervisor Dr. Sullivan (Peter Facinelli) lures her to a room under the guise of checking on a patient, but he uses the opportunity to try to pressure her into sex. Quinn turns down his advances but he forces himself onto her before apologizing for his actions. In the hallway Quinn tries to talk to Nurse Amy, but Dr. Sullivan calls her to check on a patient to thwart Quinn.
At her own home Quinn researches the app as well as watches a video about it, and reads comments disputing the video as fake. Then she sees the ghost of Evan which freaks her out and causes her to go sleep in her car. The next day her sister awakens her and they go inside. Their father is out of town and has left Jordan in the care of a family friend, who she has ran away from. Jordan and Quinn get into it after Jordan isn’t allowed to stay over at her sisters and she says she’s going to download the app and invite the boy from earlier in the movie over as she leaves. Quinn goes to buy a new phone from the cell phone store, and freaks out when the app redownloads itself to her new phone, even with a new number, SIM card, and service. In her car, she sees the cloaked figure in the rear view, and ends up backing into somebody’s car when it attacks her. The other driver confronts her and Matt (Jordan Calloway) comes to her defense, as he also was there about the Countdown app. They go to the hospital to talk to the priest and Matt is attacked in the bathroom, while Quinn is confronted by the HR department, as Dr. Sullivan has reversed the story to blame Quinn, and she is subsequently suspended. At a bar they trick another patron into downloading the app so they can review the user agreement, and figure out that changing any plans that were going to result in their death is what violates the user agreement. The two go talk to another priest (P.J. Byrne) who may be able to tell them about the demon stalking them. He tells them that he may be able to help them more if they have the app hacked, so they return to the phone store from earlier and bribe the store manager (Tom Segura) to do it. They add more time to their app, as well as to Jordan’s, since she downloaded the app and is supposed to die three minutes before Quinn. Later that night Matt spends the night with Quinn, and they are both alerted that the countdown clock has reverted back to its original time. Quinn is then attacked by the demon, as well as her sister, who they rush over to save at the babysitters house.
The three return to the priest, who tells them the code of the app is in latin and tells them about a demon from the biblical days who tortured a King for avoiding his death. A Gypsy told the king he was supposed to die in battle and he sent his brother to fight in his place, but the brother did not die. They perform a ritual involving blessing some salt in a ring to keep the demon away. The demon shows up and manages to lure Matt outside of the ring by setting off a deafening alert that everybody can hear except Matt, who is apologizing to the ghost of his dead younger brother, who the demon took the form of during the attack at the hospital earlier. Matt was wracked with guilt for stealing his brothers dinosaur while he was dying at the hospital when they were younger. The brothers eyes turn green and the demon drags him outside with Quinn and Jordan giving chase. Outside they find Matt is ok, but he instantly gets hit by a truck and pinned up against a tree where he dies. Quinn starts crying and begins to accept her fate when she discovers that her sister was impaled in the abdomen during the pursuit of Matt. They rush her to the hospital where Dr. Sullivan tends to Jordan. Quinn is taken aside by another coworker who tells her that she also was sexually assaulted by Dr. Sullivan and that if she wants to step forward legally that she will back her up. Quinn goes into Dr. Sullivan’s office and seduces him to come to the under construction wing of the hospital, where she launches a plan they discussed with the priest, that if somebody dies before they were set to, it will defeat the demon. Quinn tries to inject Sullivan with an overdose of morphine but the demon drags him away as they fight. Jordan shows up and the demon chases her and throws her through a window into another room. Quinn gets the demons attention by beginning to inject herself with the morphine, and the demon changes into the form of her mother and attempts to stall Quinn long enough for the remaining seconds to tick away so it can take Jordan. Quinn resists though and injects herself and causes the demon to turn into ash. Jordan runs over to her collapsed sister and cries over her dead body. Then she notices Quinn had written on her arm a diagram of where to inject narcan, and sees a syringe full of it in her pocket. She injects her and brings Quinn back to life as they hug.
The movie ends with Quinn, Jordan, and her dad at her mother’s grave visiting. As they leave, Quinn gets a new notification…Countdown has finished updating to version 2.0 on her phone.