A few days ago, Sylvie and her boyfriend were getting busy in the hospital room because it was his dying wish. In the present, Sylvie goes to the Brussels Airport and notices Terenzio arriving in a very bad mood. Nearby, an Asian man loses the call he was having with his home.
Sylvie is late and the desk tells her she may not be allowed to board. When she asks about the other passenger, Sylvie shows her an urn with her boyfriend’s ashes, so the clerk promises to do something. At the same time, Terenzio cuts in line and explains he needs to hand an item to a passenger, claiming he’s with NATO.
The clerk can’t let him pass without a security escort, so Terenzio pretends to give up and goes to another desk to buy a ticket. Meanwhile influencer Ines loses her call with a friend in New York, who was choking before collapsing. Inside Flight 21's plane, flight attendant Gabrielle notices her coworker is pregnant and wonders if the father is the co-pilot Mathieu.
Her coworker explains Mathieu doesn’t know about it and she’ll tell him when they land. Soon Flight 21 starts filling up. Rik notices that Nabil is trembling and sweating a lot, but Nabil says he’s just scared of flying.
Back to Terenzio, he’s having a drink to calm his anxiety and sees on the news that the host has collapsed, followed by a scene of people laying unconscious on a Melbourne beach. He says that time’s up and nervously leaves the bar, not wanting to wait for his late night flight anymore. Suddenly Terenzio punches a security guard to steal his rifle, then he runs through the access corridor as he screams to make everyone move out of the way.
Seeing this, Gabrielle rushes to close the door, but Terenzio opens it again and pushes his way inside. He forces Gabrielle to lock the door, leaving the main pilot and the other flight attendant outside. Next Terenzio goes to the cockpit and tells Mathieu to take off or they’ll be killed by the sunrise.
Technician Jakub knocks on the cabin's door and says they’re calling the police, distracting Terenzio enough for Mathieu to try to disarm him. However Terenzio shoots and hurts Mathieu's hand before asking him to fly the plane. When Mathieu explains he can’t do it alone, especially now that he has a wounded hand, Terenzio goes to the corridor and asks for any pilots.
Sylvie comments that she has piloted helicopters before and she’s dragged to the cockpit. Gabrielle makes everyone sit down and fasten their seatbelts while Mathieu calls the control tower to request takeoff, but he gets no answer. Under Terenzio’s pressure, the plane takes off anyway.
Once it’s stable, Mathieu demands an explanation, and Terenzio insists he’s a NATO officer. He only knows that the sunlight will kill them all, and that’s why Asia and the Americas have already been affected. Terenzio wants them to confirm the story on the radio, but he accidentally destroyed it when he shot.
He still demands Mathieu to keep going west without stopping. In the meantime the passengers don’t have wifi even though the tickets included the service and Ines wonders if this is connected to what happened to her friend. Rik still thinks Nabil is suspicious, so he silently gives Gabrielle a note saying that Nabil is a terrorist and she warns Jakub.
In the cockpit, Mathieu is bleeding heavily and Sylvie convinces Terenzio to let her look for a doctor. Laura volunteers because she’s a health care aide and she’s brought to the cabin too. While she checks the wound, Mathieu convinces Terenzio to let him talk to the passengers.
Using the announcement system, Mathieu lies to avoid panic, saying that Terenzio will leave at the next airport and that they’ll fly to Moscow without him. While Terenzio goes to the cabin, Sylvie proposes to land at the international airport in Iceland and Mathieu agrees, saying the presence of an unknown plane will get the attention of the authorities. Laura has cleaned Mathieu's hand but she has no tools to close the wound, so they heat up a knife to cauterize it.
In the cabin, Terenzio argues with the passengers and loses his mind, but they shut up when they hear Mathieu scream. Meanwhile Horst asks Gabrielle about the wifi and she says it’s been broken all week. When Laura returns to the cabin, she and Ayaz admit to each other that they heard something about the sun.
Suddenly Nabil starts coughing like crazy and Laura wants to help him. When Terenzio tries to stop them from moving, Ayaz uses the chance to disarm him and makes Gabrielle lock him up in the bathroom. Then Ayaz threatens Mathieu, demanding the truth.
Mathieu explains he lied to trick Terenzio and that they’re actually going to Iceland where the authorities can arrest him. This story is believed and Ayaz hands over the weapon, which Jakub puts away. Moments later the plane is getting closer to Iceland.
The radio still isn’t working so Mathieu decides to fly above the airport to check the situation before landing. To his shock, the whole area is on fire and there are desperate people trying to escape. Sylvie wants to help, but Mathieu points out he can’t land because the runway is also on fire.
Finally believing the sun story, Mathieu frees Terenzio, who demands to have his gun back before answering questions. He tells everyone that the sun will kill them and that they must keep going west, but Mathieu explains they don’t have much fuel left. Sylvie finds that the closest airport is in Scotland, so Mathieu agrees to go back despite Terenzio’s protests.
If they make good time it’ll still be dark there. Meanwhile Nabil continues to be ill. Osman manages to communicate with him in Arabic and learns that Nabil swallowed diamonds.
When they get close to the Scotland airport, the engines start failing and Mathieu cuts them off. Then he tries to slide the plane in, which causes a lot of shaking but thankfully still lands safely right before it crashes against a building. Ignoring Gabrielle’s warnings, Ines activates the inflatable emergency slide and immediately leaves the plane with the others soon following.
Now their phones are working again and they receive news reports proving Terenzio’s story. At that moment three soldiers from the Royal Air Force arrive in a truck and tell them the world ended. There are no people left in the airport except for these soldiers, who explain they must keep flying into the night.
A flashback shows Jakub and his wife discussing their plans to have children. Jakub is sad that he has a shift at the airport on the night his wife is fertile. In the present, Jakub keeps trying to call his wife to no avail.
In the plane, Laura tries giving Nabil chest compressions but it’s too late: he’s already dead. The soldiers inform them they have 45 minutes until sunrise, so they have to fuel up and take off towards the west quickly. Jakub complains because he wants to go back to Brussels to save his wife, but the others call him out since it’s obvious they would die trying.
While Mathieu and the soldiers fuel up the plane, the others search for supplies in the airport. Nabil’s body is thrown in the cargo, where Ines finds a bottle of alcohol that she hides in her purse. Meanwhile Zara says the sun story is a lie and that she wants to stay here with her sick son Dominik because flying isn’t good for his lungs.
When Sylvie tries making her see reason, Zara slaps her. Sylvie responds by capturing her and Laura injects her with a sedative to carry her back. The plane soon takes off and John explains to Sylvie and Mathieu that they need to keep a high latitude in order to stay in the dark while presenting a map with flight range annotations.
Since John has flying experience, Sylvie lets him be Mathieu’s copilot. Meanwhile soldier Roger and Ayaz are trying to fix the radio and the wifi by opening the plane’s floor with a blowtorch, hoping to find the comm system. Sylvie notices Jakub is upset over his wife and shares that she lost her boyfriend, admitting the she even considered self-deleting.
She points out that even if they lost their will to live, there are people who need their protection and that he may feel better if he’s useful. Jakub joins Roger and Ayaz acts as a translator between them. Sadly Jakub says that the radio is too damaged for repairs.
Thanks to Horst’s meddling, they get the internet working again. Many passengers get messages from their loved ones saying goodbye, leaving them devastated. Rik finds an article about the theory that this was caused by changes in the sun’s polarity.
Horst finds it interesting and reveals that he’s a climate scientist working for the European Commission. He explains that it’s normal for the sun's polarity to reverse once every eleven years or so, but there have been weird, unexplained anomalies lately. He thinks that this time the reversal may've been unusually strong and resulted in very high levels of gamma radiation.
While soldier Freddie unsuccessfully flirts with Gabrielle, Ayaz speaks to Sylvie in private. He’s researched the three soldiers online and learned that they were accused of murdering a translator and abusing his wife in Afghanistan. Minutes later Freddie finds the bottle Ines hid and scolds her since supplies were supposed to be kept together for everyone.
When Ines explains it’s just a prototype for a label she’s launching, Freddie opens the bottle just to be a contrarian. The pop scares Laura’s senile patient, who thinks it was a gunshot and runs to try to open the emergency exit. Freddie immediately pulls him back, only for the man to accidentally his head and instantly die.
Everyone starts blaming Freddie for not being careful and Freddie snaps so he takes out his gun. Roger has to cut in and calm him down. Afterward Mathieu tells everyone to sleep before they land in Canada for supplies and hopefully a radio.
Ines says that there were no updates on Belgian sites in the last two hours, which implies bad news for their families. Sylvie uses the excuse of changing Mathieu's bandages to speak to him in French and tells him the truth about the soldiers, who were probably left behind on purpose. Eventually the plane lands on Canada with two hours left for sunrise.
Mathieu asks the soldiers to search for a radio, but they get suspicious so they make Jakub and Gabrielle come along. The group takes a truck to drive through town and Gabrielle is horrified to see bodies inside a school bus. Meanwhile Mathieu tells the other passengers the truth about the soldiers.
Jakub will try to lose them, so they must grab supplies and be ready to leave quickly. Ayaz and Osman prepare Nabil’s body and give him proper burial. Rik and Horst examine a random dead body in the airport and notice the tongue looks like microwaved meat.
In town, the group makes it to a store and Jakub finds a new radio, but he doesn’t tell the others. When the soldiers go looking in the back room, Jakub locks the door behind them. Not knowing the truth, Gabrielle is now scared of Jakub and refuses to follow him.
Jakub runs as the soldiers shoot the lock to open it and come after him. Stealing another car, Jakub drives away and the soldiers follow him in the truck. Gabrielle is left behind to die in the morning.
Soon Jakub makes it to the airport and gets in the plane just in time. As it starts to move, the soldiers run after it with open fire, damaging a window. A flashback shows Mathieu doing the naughty with the other flight attendant.
At that moment his wife arrived so the attendant ran to hide, however the wife saw the female clothes on the floor anyway. In the present, the plane has taken off safely, but they don’t know how long the damaged window will last. Terenzio is tired that Mathieu is making all the decisions and wants them to work together, so an argument ensues.
Suddenly they hear someone on the radio from another plane claiming that there’s an underwater facility in Hawaii called the “Mars Sphere” where astronauts were trained. It can hold one hundred people and the water is protecting it from the sun. The other plane found the coordinates painted on a wall so they guess someone was spreading the message.
Mathieu announces they’ll be going to Hawaii and Terenzio gets mad again, triggering another argument. Sylvie goes to the cabin and learns that Rik and Terenzio won’t let the others eat until they agree on some rules. If Hawaii doesn’t work then they must choose the next destination together, everything must be shared equally, and no one gets kicked off the plane unless they all vote on it.
Ayaz and Terenzio almost get in a fight, but they’re interrupted by a sudden alarm. Sylvie rushes to help Mathieu, but the alarm just shuts down on its own only for another one to start. Since these two alarms aren’t connected at all, Mathieu concludes one of the soldiers managed to climb onboard during the chase and now is messing with the cables.
When Mathieu goes to talk to the passengers, Ines informs him that she found Gabrielle on Instagram and she made a post saying she didn’t blame them. Then Mathieu tells them about the soldier and explains he’ll take more altitude to let the lack of oxygen knock the soldier down. Ines tries to get some water and Terenzio makes her trip.
Another argument begins while Laura notices that the crack on the window is getting bigger. In a few seconds it finally breaks and the plane loses pressure as it begins to shake. Everyone rushes to put on the air masks and help each other stay on their seats while Mathieu and Sylvie work hard to stabilize the plane.
In the chaos, Jakub manages to find a panel and covers the window, which puts the plane back to normal just in time. After another argument, Mathieu announces they can’t go to Hawaii for now because they can’t fly fast enough to get there before sunrise. They’ll have to find fuel first.
Dominik's having trouble breathing, but thankfully Ayaz knows a trick with the pipes from the air masks that helps him breathe again. Suddenly an alarm wails and Mathieu discovers that the hydraulic system isn’t working properly. Someone will have to head deep into the plan and get the soldier out since he’s obviously causing this.
When Terenzio starts complaining again, Mathieu agrees to vote for everything just to shut him up. Everyone votes in favor of kicking the soldier out and it’s agreed that Ayaz, Jakub and Terenzio will do the job. Using the blowtorch, they open a hole and get inside the plane's cargo compartment.
Mathieu returns to the cockpit and discovers Sylvie has found an airport nearby. Without consulting the others as promised, Mathieu turns the plane in that direction. Laura talks to Zara and learns about Dominik’s poor condition.
Then she goes to see Mathieu and asks him to fly lower so Dominik can breathe a little better. Mathieu refuses at first because it would use more fuel, so Laura reveals that Gabrielle left a message on Ines’ Instagram saying that the other flight attendant was pregnant with his child. Feeling guilty, Mathieu starts flying lower.
Meanwhile the three men keep making their way through the plane. When they finally make a hole that gets them to the wheels, Freddie reaches inside and grabs Terenzio’s gun to bite his fingers. Terenzio lets go of the gun and Ayaz takes over, quickly shooting Freddie dead.
Afterward the trio returns to the cabin where everyone is looking serious. Osman has told everyone he saw blood on the blanket that covered Nabil’s body and that Ayaz sent him away mid-burial, so he thinks Ayaz cut Nabil open to get the diamonds. Ayaz takes out a bunch of emeralds and admits he did open Nabil, but he didn’t kill him.
In fact, he was the one who paid Nabil to smuggle the emeralds, and Nabil died because he didn’t follow the correct packing procedure. Rik reveals he has handcuffs because he’s a security guard and wants to keep Ayaz cuffed for now, which everyone votes in favor of. A new flashback shows Ayaz walking down a red-light district and entering a naughty house.
His guards were holding down a man that hurt one of the workers. The man threatened to call the police, but Ayaz explained they were all under his bribes. He told the guy he could leave if he left his watch as payment, but the man refused.
Then Ayaz took out a whip and started hitting him with it. In the present, the plane has landed on Alaska and Jakub can finally repair the window properly. Mathieu gets to fuel the plane up again but because of the incoming sunlight, they can’t go to Hawaii yet, they must keep going west.
Rik keeps insisting they should kick Ayaz out and is frustrated because Terenzio doesn’t back him up anymore. When the group enters the airport to look for supplies, they bring Ayaz along for a trial, learning he was a dealer and a hustler. Ayaz explains he had to escape his homeland and ended up doing crime just to survive because Belgium isn’t nice to outsiders.
Terenzio interrupts the conversation to say they should go back to Brussels because his fellow NATO people mentioned a bunker. He doesn’t know where it is, but there should be documents. To Rik’s shock, Terenzio also says they should keep Ayaz because he works well during a crisis.
The others are wary, so Terenzio vouches for Ayaz and promises that if something happens, both of them will leave the plane. Most of the group votes in favor and they take off again. In the plane, Sylvie asks Ines to go online to research the facility in Hawaii and the possible NATO bunker.
Afterward Horst tells Sylvie and Mathieu that the fruit they picked up in Canada has no taste. He theorizes the sun incident is breaking the food’s DNA, meaning it has no nutritional value. It seems it’s only affecting fresh food and canned stuff is fine.
Moments later the plane starts going through some turbulence. Sylvie rushes back to the cockpit but Mathieu has already solved the problem. He starts laughing like a maniac and Sylvie worries that the lack of sleep is affecting his mental health.
She tells him to rest because she can take over, but he refuses. Then Sylvie brings Ayaz and Rik over and the men drag a yelling Mathieu out of the cockpit. Noticing everyone’s judgement, Mathieu finally agrees to rest and goes to the bathroom.
Suddenly they hear a message in Russian on the radio and bring Zara to translate. Because of the static it isn’t entirely clear, but it appears to be an astronaut in the International Space Station repeating the words “Stara 17”. At the same time Ines informs Sylvie and Jakub that the Hawaii safe haven was never completed, so they can’t go there.
Mathieu is needed to choose new coordinates and everyone realizes they haven’t seen him in a while. They open the bathroom and discover he’s passed out. Laura theorizes his wound is infected, so they’ll have to amputate his hand.
She isn’t a surgeon and she doesn’t have the right tools, so she doesn’t think she can do it now. The group agrees they must land on Brussels like Terenzio wanted. The group asks Sylvie, who explains she doesn’t know how to land a plane but they convince her to use an online video.
She reluctantly agrees to do it but points out taking off is much harder, so Mathieu will have to recover for them to leave again. Jakub brings over a phone and starts guiding Sylvie through the landing process. Sylvie is about to have a panic attack, but Jakub helps her stay calm.
As they get closer to the airport, the engine starts failing and the whole plane shakes like crazy. The duo doesn’t give up and after Sylvie turns off the engine she manages to land the plane, which slides on the runway for a few miles until it stops. The group claps for their work and Sylvie announces they have two and a half hours before sunrise.
They start dividing tasks to do in town while Jakub announces he’ll stay to figure out what happened to the engine. Horst realizes that the fuel is organic-based, meaning it’s affected by the sun phenomenon like the fruit. A flashback shows Rik returning to his house.
After helping his mother with her hearing aid, he goes to his room and uses his computer to talk to a Russian girl who keeps asking for money. Not realizing it's a scam, Rik announces he’ll visit her soon, and the girl stops answering. In the present Jakub checks the plane’s fuel and notices it looks like maple syrup.
There isn’t much left though, so getting new fuel should dilute it. However finding fuel that wasn’t affected by the sun will be hard. Osman explains he used to work for a fuel terminal and remembers the tanks were beneath the river, meaning they should be protected by the water.
Jakub and Osman agree to drive to Amsterdam to find that fuel. Meanwhile Terenzio, Rik, and Ayaz arrive at NATO headquarters, where they find dozens of bodies on the ground. Terenzio takes them to the room where he heard the ambassadors talk about the sun and they start searching for any useful information.
Rik notices security cameras and decides to find the footage to see if they can learn more. After Rik leaves, Terenzio starts making nasty comments about Ayaz’s homeland and Ayaz slaps him for it. Terenzio punches him in return and a fight begins.
At first it looks like they’re equal, but Terenzio manages to land a strong punch that knocks Ayaz out. Then Terenzio joins Rik, who has been watching the footage. He’s learned that there’s a bunker in Bulgaria mentioned together with “Stara 17”, the same words the astronaut said on the radio.
Rik asks where Ayaz is but Terenzio tells him that he went back to the plane with more supplies. He also says he got hurt because he fell. At that moment Rik sees Ayaz’s unconscious body on a screen but Terenzio quickly turns it off and urges Rik to leave.
Laura, Horst, Zara, and Dominik take Mathieu to the hospital. Dominik goes ahead to search for a wheelchair and screams when he finds a corridor full of bodies. While Zara gathers medicine, Horst and Laura rush to a surgery room and have to move a man that died on the table.
Laura starts operating although she doesn’t really know what she’s doing. Meanwhile Dominik follows a strange noise and finds a moving bag. When he opens it, a strange animal jumps out and runs away.
Zara finds him and grabs the bag to bring it to Horst, showing the dog food inside. Dominink described the animal as “a rat but not a rat” and Horst thinks the boy imagined things. Laura finishes the operation but is reluctant to move Mathieu because he isn’t stable yet and his heart could stop.
However they’re running out of time and they have no choice but to put Mathieu on a stretcher. At the airport, Sylvie and Ines are looking for food and also find tons of bodies. After seeing a couple that died together, Sylvie needs a moment alone.
Ines tries following her, however Sylvie gets on a vehicle and drives away. Moments later Jakub and Osman come back with some fuel. Hearing Ines’ story, Jakub goes looking for Sylvie, who is at her old house with her boyfriend’s ashes.
Soon Terenzio and Rik also make it to the airport, and Rik gets suspicious when Terenzio fakes surprise at hearing Ayaz didn’t make it. Soon Jakub finds a crying Sylvie at her place. After sharing how upset she is, she kisses Jakub, who doesn’t kiss back.
Sylvie pulls back and apologizes, explaining her emotions got the best of her. In NATO, Ayaz is painfully crawling out of the building. In the plane, the hospital team brings an awake Mathieu to the cockpit.
He concludes the fuel isn’t much and that he’ll need lots of help to pilot. Thankfully Sylvie comes back just in time to team up with him again. Meanwhile Zara demands to know the truth about Ayaz and Rik shares his suspicions.
A furious Terenzio pushes him down and says Rik was the one that hurt Ayaz. Zara doesn’t want to leave without him, but they don’t have any time left. The plane gets ready to take off but they stop when they see Ayaz arrive in a car.
Suddenly Terenzio appears proudly wearing a military uniform. He gets into a fancy sports car where Ines is waiting to tell him how cool he is as she gets affectionate. At that moment Terenzio wakes up, revealing he’s been banished and handcuffed under the floorboards.
Meanwhile the others check a map and learn that the coordinates Rik got from NATO match a hydroelectric dam in the Stara district, so they think there may be a hidden bunker under the water. Unfortunately they’re missing a few decimal points to the coordinates so they aren’t sure exactly where it is. They’d only have thirty minutes to search before the sun rises, but they don’t have any other options since they don’t have enough fuel to go somewhere else.
Zara speaks privately to Ayaz, who has offered to carry Dominik during the search. She explains that she’s not sure she’ll be able to run for long because she’s weak after selling her kidney to be able to pay for Dominik’s treatment. Zara makes Ayaz promise to carry her son no matter what.
Afterward Rik apologies to Ayaz for leaving him behind and insists Ayaz should hurt him to make it even. Instead Ayaz tells him of his time in prison and how he never returned to his family. In return Rik tells him about his online love and shows him a picture of her.
At that moment Ines walks in and recognizes the model in the picture, so Rik finally realizes he’s been scammed and throws the photo in the trash. Minutes later Mathieu announces they’ll be landing soon. Then Sylvie asks the group what to do with Terenzio.
Most of them want to leave him, but Ayaz doesn’t want to possibly die while having "killing a man" as his last action so Sylvie agrees to bring him along. Eventually the plane lands and they find two vehicles nearby, so the group immediately splits into two to start searching as fast as possible. In the hurry, Sylvie forgets her boyfriend’s ashes.
A few miles later, Ayaz stats having a fit while driving, causing the car to crash and Dominik to pass out. Ayaz is in a frozen state and Horst has to snap him out of it. The car won’t start again, so this group has to continue on foot.
Even in this condition, Ayaz carries Dominik and confesses to Zara that he’s been having those fits since Terenzio beat him up. They want to call the others but there’s no signal, so they take whatever road looks best. With only eighteen minutes left for sunrise, Sylvie’s group finds the facility and goes inside, noticing the gate shutting behind them automatically.
Osman runs to try to keep it open, only to get an electric shock that knocks him out. The others find a button that opens the gate, however if they don’t keep it pressed the gate closes again. Terenzio volunteers to stay with the button while waiting for the others, but Sylvie doesn’t trust him and handcuffs him to the pole before tossing the keys to the ground.
If Terenzio wants freedom, he’ll have to open the gate for the others. Then Sylvie and the others keep on moving, finding tons of army vehicles among the way. Eventually they find a locked door, so they hit it with rocks until they break it open.
Everyone rushes inside except for Sylvie, who wants to wait for the others. Soon Ayaz’s group arrives near the facility but there’s an old gate in the way. Ayaz wants to climb it, however Zara translates the sign and says it’s electrified.
Horst says they should stand on something non-conductive to avoid the shocks and the group starts removing a tire from an abandoned truck since it's made of rubber. They also cover the razor wire with shirts and jackets. Horst climbs first and teaches them to never touch two wires at the same time.
He jumps to the other side safely, so Ayaz follows with Dominik. Just as the sun is about to come up, Sylvie finally finds Ayaz’s group and they all run to hide inside the facility just in time. Terenzio tries breaking the handcuffs and reaching the keys to no avail, so he looks at the sun and waits for the end.
Inside the facility, some soldiers welcome the group and ask for their help solving a new problem.
