In 2048, our planet is overpopulated and has lost access to almost all natural resources. The government begins a program that will genetically modify fourteen soldiers to go to Saturn's moon Titan to start a new civilization there. These fourteen volunteers and their families are moved to their very own neighborhood and given luxurious technologically advanced houses.
Former pilot Rick is one of these volunteers and he brings with him his wife Abigail, who is a doctor, and their child Lucas. The head of the program Doctor Collingwood has lots of hope for Rick's development because when he was in the air force, he was shot down and had to cross the Syrian desert injured and alone without food or water for three days, which proves he's a tough survivor. Both Rick and Abigail are doing this for their son because they want him to have a future, but Abigail admits to Collingwood she's a little worried that Rick will get very sick.
Collingwood confirms this may happen, but she doesn't need to worry because all Rick will need is proper aftercare. Once all the volunteers have finished moving, they have their first meeting with Collingwood to start the treatment. First he does a presentation about the program, explaining how we've destroyed the planet and that Titan is the place to go next because it's the only other place in our solar system with an atmosphere and primordial ecosystem.
However it also has liquid methane raining into huge oceans and lakes they can't swim in and an atmosphere rich in nitrogen that they can't breathe, it's simply too cold to live in. This is why instead of terraforming, they've decided the genetically modify humans to adapt to Titan's natural characteristics. One of the volunteers doesn't understand how the bodies won't reject the treatment, and while Collingwood explains the clinical trials were successful, he also admits there's no guarantee everyone will survive.
The volunteer continues to question the program, but Rick shuts him up and tells him to leave if he doesn't like it. The volunteers come from all over the world and they were chosen because they all survived extreme circumstances. After the meeting is over, they are given cardkeys to have full access to the base and taken to the lab for their first shot out of 300 that they'll be getting for the next few weeks.
Doctor Freya tries to explain what each shot is for, but Rick only understands half of it. Rick's family starts a new routine from then on, but it's nothing out of the ordinary. Lucas goes to school, Abigail takes care of the house, and when she's allowed to, she sits with Rick through the different treatments.
All the volunteers become fast friends and they start to hang out together outside the base, being neighbors allows them to throw dinner parties and barbecues all the time. Sometimes the conversations during these parties turn a little dark, like when one of the volunteers admits he's afraid that after the two years on Titan they agreed on, they won't be allowed to come back. One day, their barbecue party has extra amounts of drinking because this is the last time the volunteers are allowed to consume alcohol.
In the evening, Abigail feels dizzy because of how much she drank, so Rick helps her go upstairs. However he's the one that ends up falling as he begins to cough a lot, feeling like he can't breathe. Abigail checks on him and notices he's burning with fever and immediately drags him to the bedroom, where she gives him medicine and tucks him in bed, keeping him company for the rest of the night.
Sometime later, Collingwood is very pleased with how the volunteers' DNA samples are progressing, meaning it's time for a big test. The group is asked to spend a long time underwater without an oxygen tank, and after the half-hour mark, only Rick and Tally are left, making a little competition out of it. In the end Tally makes it to 39 minutes, but Rick manages to stay down there - in fact he's so comfortable that he begins swimming in the pool.
This shocks everyone because Rick isn't swimming like a normal human, he's going at a high speed while moving like a dolphin. In the evening, Rick shows off this new move to his son in the garden pool. Afterward, he tucks Lucas in, and the kid surprises him by bringing up his dead grandfather, who he's sure would've loved all this.
Then he joins his wife at the pool to get frisky in the water, but Abigail pauses things when she notices some black veins on Rick's body. Rick wonders what's wrong, but just like that the blackness is gone, and Abigail decides to ignore it for now. Some days later, the volunteers go through their first surgery.
One of the wives named Rayenne visits Abigail to let their kids play together, and she shares some of her worries. She confesses that she's terribly scared and that she doesn't think her husband belongs here, so Abigail comforts her by reminding her the volunteers will save humanity and most importantly, their kids. Rick comes out of the surgery in great health and returns home to continue spending time with his family.
Abigail is happy to see him well, but she also worries about the potential side effects she reads about in the manual they gave them. Later that night, Abigail wakes up to find the bed empty. Rick turns out to be in the kitchen, putting some ice on his skin because he feels very hot.
Abigail prepares a bigger bucket of cold water for him, and Rick challenges her to a little game. They both put their hands inside the bucket, and while Abigail has to take them out after a few minutes because she can't stand the cold, Rick keeps them there, confirming he can't feel the cold anymore. The next morning, they go for a run together, and they stop to admire a special spot by the road that has the most beautiful view of the area.
Rick laments not being able to save the planet. The different experiments continue, which include running with masks that simulate Titan's atmosphere and swimming for long periods of time in freezing water. Sometimes a volunteer can't take it and must leave for the day, but in the case of Tally, she's stubborn and wants to stay in the water even when she can barely tolerate the cold.
To help her, Rick teaches her to meditate underwater. One afternoon after the testing is done, the volunteers are in the showers, and Rick notices he's losing hair. Tally confirms it's happened to her as well.
Suddenly they hear screaming and discover one of the women is having a seizure while throwing up blood. The doctors rush to help her, but nothing they can do can save her and the volunteers meet the first death in the group. Later that day, the volunteers have a meeting to discuss what happened.
Some of them are worried about dying too, but the others remind them that they always knew the risk. Although they shouldn't drink, they decide to do it anyway to help them cope. While Rayenne comforts her husband Zane outside, Tally's husband Andrew helps Abigail in the kitchen.
He shares the story of how they met and how he fought to get together with Tally until the end, then Tally joins them to point out that now Andrew is desperate to start a family. When Andrew leaves to put the dishes on the table, Tally confesses Andrew thinks she'll leave for two years to get it out of her system and become a good wife, but she wants more than that. Moments later over dinner, Abigail notices all the volunteers have their veins occasionally getting black.
Suddenly they hear screaming coming from the garden: Zane is having a breakdown and attacking Rayenne. The other guys immediately rush outside and hold Zane down until he calms down while Abigail takes Rayenne away. The next day, Freya comes to the neighborhood to give the volunteers extra medicine that will stop them from having the same problems that the dead woman and Zane did.
Abigail notices some of those doses are pretty high and asks to talk to Collingwood, but he isn't available. Later in the evening, Rick finds himself throwing up with blood included. Abigail tells him to rest while she cleans, and once Rick isn't watching, she takes a sample of his blood.
Afterward when she moves around the house to lock all the doors, she finally notices there are cameras hidden in the house so that the people at the program can watch them 24/7. The next time Rick uses the pool, he begins to notice his skin is peeling off, but he doesn't seem too worried. When they go to bed, Abigail notices the state of Rick's skin and the fact he's losing hair, making her worry worse.
The next day, Abigail looks at Rick's blood in a microscope and discovers it's turning black. Sometime later the volunteers go through the next big procedure, which consists of making their eyes similar to a cat's so they can see in the dark. The surgery goes well, but Rick has to keep his eyes bandaged for a while and his family has to help him around the house.
One night, Abigail hears Rick groaning in pain as his eyes begin to bleed. They take him to the lab for another surgery, and Abigail approaches Collingwood to ask what's going on, pointing out that something is alive inside of Rick and that she knows about the cameras. Collingwood explains that he didn't want the cameras, but they were an order from the Pentagon for security, and that Collingwood being blind is part of the process, he'll be fine in a few days.
Abigail thinks there's more he isn't telling her, but Collingwood sends her home. Abigail goes to her house and begins packing some clothes for Rick when she suddenly hears some sirens. When she comes out, she discovers the army is surrounding Zane's home.
She isn't allowed to come closer, but she still sees the terrifying sight that happens next: a mutated Zane throws Rayenne through the window, instantly killing her. The soldiers break into the house and shoot at Zane, killing him too. Later at the base, Abigail is watching over Rick and hears more soldiers arrive.
Since Collingwood will be busy dealing with this mess, Abigail takes the chance to take Rick's cardkey and goes snooping. After hiding at strategic spots to avoid security, she enters Collingwood's office and finds all the files indicating that the volunteers are having their DNA infused with animal DNA to reach the next evolutionary step, which Collingwood has called "Homo titaniens". Meanwhile Collingwood is having a meeting with Colonel Solano and the people from NASA, who want to shut down the program and call it "unproven science".
The volunteers are becoming violent and this is entering a criminal area instead of being about space, the last people who tried something of the sort were the Nazis. Colonel Solano wants this experiment out of his base, but Collingwood and his advisor point out that the Ministers of Defence have the last word, so they aren't leaving unless they say so. After the meeting, Freya also tries to tell Collingwood that they should stop, but he dismisses her.
When Rick is sent home, Collingwood comes along to explain his sight will return in 24hs. They had miscalculated the brain's ability to process enhanced senses and Zane's mind simply overloaded, but a new surgery could fix things. Abigail finally snaps and demands to know the truth, thus Collingwood finally admits they're injecting animal DNA into the volunteers.
He can't guarantee that it'll work so he understands Abigail's worry, but he also points out they've always known there would be risks. Rick needs to go through this new procedure to survive; Abigail hates hearing this and stays distant for a while. A day later, Rick removes the bandages and confirms his sight is fine, he also shaves his head to avoid having bald spots.
When night falls, he discovers he can see every detail in the darkness and he's so impressed that he calls Collingwood to confirm he'll do the procedure. While the families stay home, all the volunteers are put through surgery, but there are lots of complications and most of them die. In the end, only Rick and Tally are left alive and healthy.
The next day, Andrew, Abigail, and Lucas visit Rick and Tally, and they are shocked to discover they've become some kind of mutated creatures that only communicate through tactile contact and a low-frequency that humans can't hear. Rick puts his hand against the glass that separates them, making Abigail cry, and her tears get worse when Collingwood gives her Rick's wedding ring. In a few days, Tally and Rick will be leaving for Titan, but meanwhile they're allowed to stay home.
Rick has trouble putting on human clothes and when Abigail tries to help him, Rick accidentally hits her. He tries to check on her, but now Abigail's so scared of him that she can't help moving away from his touch. Rick spends most of his time in the pool, feeling more comfortable there than in the house.
One night after putting Lucas to bed, Abigail looks outside and discovers Tally entering the garden with her hand covered in blood. Rick doesn't look bothered by this and approaches Tally so they can communicate through some weird tentacles that come out from their fingers. At that moment, the army arrives in the neighborhood and finds Andrew dead in the shower.
They begin approaching Abigail's house too, causing her to run upstairs to hide with Lucas. The soldiers shoot Tally with tranquilizer darts, and it takes quite a few of them to knock her down. However when they come closer, Tally reveals she's awake and uses the tentacles to kill one of them.
The others immediately respond by opening fire to kill her. Next the soldiers try to come after Rick, but he easily knocks them out with his new strength. Rick tries to drown the last soldier in the pool, but Abigail hears the commotion and comes out to stop him.
Unfortunately it's too late, and realizing what he's done, Rick runs away. Colonel Solano calls his entire team to begin looking for Rick, ignoring Collingwood when he asks him not to kill him because he's expensive research. Abigail and Lucas are taken to the base for safety reasons, but Abigail leaves when she realizes where Rick went.
After making sure she isn't followed, Abigail runs to their special spot and finds Rick there. Abigail offers her hand to prove she isn't scared anymore, and once Rick's tentacles have grabbed her wrist, she kisses him. It's at that moment that the army helicopters find them and knock them out.
Abigail wakes up later at the base with Collingwood by her side, explaining they had to hurt her for her own good. The Pentagon is shutting down the program soon, meaning they need to send Rick to Titan immediately, because Tally proved the Earth's atmosphere will either drive them crazy or just kill these new bodies. However they can't force him to do it either because that may kill him too, so Abigail needs to convince Rick to go.
Afterward she's taken to see Rick, who is being kept inside a glass cage. Collingwood wants Abigail to give Rick a shot of quetiapine, which works as a chemical lobotomy and will erase all his memories. Abigail doesn't like this, but Collingwood explains it's the only way to make him leave.
A soldier gives her the injection with the quetiapine from a drawer, which Abigail drops just to make him pick it up. Then Abigail enters the cage, and after exchanging a meaningful look with Rick, she gives him the injection, which knocks him out. When Abigail comes out, she asks Freya to come with her while a soldier approaches Rick to get him ready for the trip.
However Rick's only pretending to be unconscious and kills the man, it's then that Collingwood realizes Abigail grabbed saline from the drawer when the soldier wasn't looking and that's what she gave to Rick. The soldiers open fire, but Rick just runs away and hides in dark rooms where he has sight advantage. Abigail goes to pick Lucas up and Freya guides them to an alternate exit, where they reunite with a heavily wounded Rick.
Lucas and Abigail hug him to prove again they aren't scared, and Freya looks for some medicine, but suddenly all the soldiers show up. Collingwood asks the women to get away or the soldiers will shoot everyone, but Abigail refuses. Furious, Collingwood asks the soldiers to open fire, but Solano stands up to him and tells him he won't shoot two unarmed women and an innocent kid.
Then he aims his own gun at Collingwood, and all the other soldiers follow his example. As Collingwood gets arrested, Abigail rushes to Rick's side, and her hug allows him to reinforce his most precious memories. Sometime later, Abigail together with Freya become researchers on the Titan II project, using more ethical methods to save the world.
Meanwhile Rick is sent to Titan, where he reveals his new body has wings and can fly around his new home.