The novel starts with the main character, Harper Lane, flying to London from the USA. Suddenly, chaos erupts and the plane crashes.
The second chapter is told from a different point of view, that of Nick Stone, also a passenger in first class when the plane crashed. He is among the first ones to come to his senses and then quickly starts to coordinate those who survived to get out of the plane. Sabrina, a doctor who survived assess the situation and advises the surviving passengers to keep calm and avoid moving excessively as there was still the possibility that some could have internal bleeding or other types of trauma.
Most of the passengers in first class survived but the plane was ripped in half and the economy class was missing. When the passengers got out, they started to hear cries in the distance and they figured that it must be the rest of the passengers.
Lane and Nick start running towards the noise and soon realize that the bottom part of the plane felt into a lake. Many survivors tried to save themselves by swimming but because of the frigid water, the weaker one died. Nick thought about a plan to help as many as he can before the plan submerges completely into the water.
Nick, Harper and a few stronger passengers decide to swim to the plane that was still in the water and try and help as many as they can before the plane goes underwater. When they reach the plane, they quickly pass over those who are still alive but the plane sinks faster than they expected it to and Harper gets stuck towards the tail of the plane underwater. She loses conscious but Nick saves her after he realizes that Harper is missing.
The next morning, Nick wakes up to find that no help came to them. What is more, no one has cell phone signal even though they crashed in England. One of the survivors, Bob Ward, proposes that they should inspect the plane and see if the pilots are still alive and maybe they could call for help. When they return to the plane, they see that an Asian man is still inside, typing at his laptop. From a list with the name of the passengers, Nick finds that the man’s name is Yul Tan. Nick and Bob are unable to make the pilots in the cabin move so they conclude that they must be all dead. Because there was no way Bob and Nick could break into the cabin, they decide to stop and get some rest. Nick returns to the bottom part of the plan but is stopped by another passenger from the first class, Grayson Shaw who has a large stick in his hands. They are interrupted by Harper who woke up and went into the woods. Shaw returns to the camp while Harper and Nick go to the front of the plane after they are told that one of the pilots survived and that they managed to open the cabin.
The pilot, Dylan, tells Harper and Nick that the plane lost radio contact with the ground somewhere above the Pacific. They were not overly concerned as one of the pilots had flown the route numerous times and was certain that they could manage it only with the radar. Then, something exploded and the plane crashed.
Nick gave Harper the key to the pilot’s cabin, thinking it that it is safer to keep it locked, taking into consideration the fact that weapons were inside the cabin.
The survivors spend a night outside and the next morning they begin to assess their situation. Nick concludes that it is necessary to find food and Sabrina tells him that they need to build a shelter for those who were affected by the cold temperature. Nick proposes that he should go and look if there are any signs of towns of maybe houses around where they could find help but Sabrina convinces him to stay, telling him that if he goes, the reaming people will become more disorganized.
Nick proposes that they dive into the submerged part of the plane to see if they can get any of the luggage from there and he also sends groups of four people to scout the areas.
Soon, the sick are moved into the nose part of the plane, including Harper who begun to feel sick and developed an infection. The people sent to scout the surroundings return bearing news about at octagonal structure they spotted in the fields.
The next day, Nick, Mike and Bob decide to investigate it. Nick recognizes the structure as being Stonehenge, but not the Stonehenge he saw as a child but a version of Stonehenge that seemed to have been recently built.
Back at the plane, Harper starts feeling worst. Sabrina tells her that the wound the she had on her leg got infected and it could out her life in danger. As they have a limited supply of antibiotics, Sabrina lets Harper decide if she wants to take any of it or if she is willing to give them to those who may need it most. Harper decides that it is better to give the pills to those who are in a worst condition than she is.
Harper’s leg gets worst and Sabrina tells her that she will soon have to start cutting away from her leg in order to try and save her life. Their conversation is interrupted when those who were outside come into the plane with wounds. Harper goes looking for Sabrina and finds her with Yul inside the pilot’s cabin talking in hushed voices about how they might have known that something was about to happen and that it was possible that someone must have caused the plane crash. Sabrina returns to the men and women who slowly fill the plane. Harper notices how everyone seems very old and soon many among them die.
After things calm down, about half of the passengers who survived the initial crash died. Sabrina and the Yul talk in hushed voices about how someone might be behind the crash and how it was strange that some died of old age while the other were not affected by the rapid aging process. They are unable to continue their conversation as a strange light appears and the passengers inside the plane are attacked.
At the Stonehenge, Nick notices how Bob is getting older and older. They concluded that something must have happened and that they are now in the future and that something must have brought them there. The question however remains if the people who brought them are hostile or not. They decide to camp at Stonehenge and then return to the plane the next morning. Unfortunately, Bob dies during the night and an unusual event forces Mike and Nick to leave earlier.
Nick sees a figure hovering in the air, almost like a helicopter but much more different, heading towards the crashed plane. Nick and Mike return to the crash site only to see the survivors being dragged into tents by figures in suits. Then, the figures on the ground are attacked by more helicopters coming from the sky. Nick manages to drag Harper, Sabrina and Mike with him and tells them to run. Nick goes back looking for Yul and is saved by Grayson when a hooded figure gets ready to shoot him.
The small group then goes back to Stonehenge and Nick and Grayson go to inspect a farm that looks deserted not too far from the structure. The two men return telling the group that it is safe and they all go inside the farm. There, Nick goes to sleep almost immediately while Harper starts to inspect the farm. When Nick wakes up, Harper tells him and Grayson what she had overheard from the conversation between Sabrina and Yul that took place in the plane.
Nick, Harper and Grayson go down into the subbasement where Sabrina and Yul are, standing beside what looks like to be a car. Yul admits that he was planning to leave but Nick demands answers which Yul doesn’t want to give. Yul tells them that it would be safer if Nick, Grayson and Harper were to remain behind while they go to London where they hoped to find help. Nick argues that he and the others will not be left behind and decides that they should split because the car recognized the fingerprint of three of them, Sabrina, Yul and Nick. Nick and Harper go into one car, Yul goes alone into another and Sabrina and Grayson go into another car together.
While alone, Harper and Nick talk a bit about themselves. Harper tells Nick that she was returning from USA where she meet with Grayson’s father, a billionaire who wanted to hire her to write his autobiography. Grayson became mad because he found out that his father wanted to leave all his money to a charity. This enraged Grayson and the tension between Grayson and Harper was a result of that.
Once they reach London, they are shocked to see the city completely deserted. They decide to go to Harper’s apartment which was close to the place where the cars let them. Harper recognizes the apartment even though they suspect that they are now a hundred years in the future. Harper finds her diary under her bed and starts to read it. She finds that she wrote the autobiography of Shadwell’s father and then wrote Sabrina’s autobiography. Soon, her dreams of writing a work of fiction were forgotten. Then, in the year 2039, an entry about the Titans appears and the hint that Harper pursued a taken man. After that, her diary ends and Nick enters her room. He notices her distress and asks her what is the problem but she refuses to tell him. Nick tells her that they will go inspect a museum nearby to find some clues about what happened.
The museum is also extremely modern on the inside but the outside is a simple design. Once inside, a hologram appears and it introduces itself as being Harper. The real Harper recognizes her older self and is shocked to see her future self. Not long after that, a hologram of Nick Stone appears as well and it is revealed that Oliver Norton Shaw and Nick Stone became partners and created the foundation The Titans. The foundation had the purpose of gathering the rich and wealthy and trying to solve problems like hunger, suffering and war. The Titan group focused on three main projects: bringing free internet for everyone, building the Podway as an alternative to mass transit that was both fast and cheap and the last project was creating a structure in space where people could live and their fourth project focused on building a dam across the Gibraltar and establishing a new country in the middle of the Mediterranean Sea called Atlantis.
The group then reaches a panel where they find personal details about everyone. Harper died at the age of eighty-nine and Grayson died of liver cancer after he tried to prove all his life that his father was interested only in making money and fame. While everyone looks at the panels trying to know about what will happen to them, Yul is the only person not using the panels. When Nick asks him if he knows what is happening, he tells Nick that sadly, he knows. Yul tells them that Q-net, the internet that revolutionized the world was his invention. A few weeks prior to the flight, when he put the Q-net into function, he began to receive strange messages that predicted the future. Through those messages, he was instructed to board to plane to London and also to contact Sabrina. When asked about what could have caused the earth to be deserted, Sabrina theorizes that it may have been a pandemic that was the result of a genetic mutation. They conclude that the world where they are in is at war and that there must be at least two fractions that fight against one another.
Their conversation is interrupted when suited figures appear in the Hall. They tell Nick that they are there to help and the reason why the plane ended up in the future was because of them. Before any other explanations could be given, helicopters appear above the Hall and start attacking the Hall. The suited figures start fighting against then while Nick, Harper, Yul, Sabrina and Grayson run away. Sabrina and Yul get separated from the group and Harper is hit and captured, Nick is saved by Grayson after he too is hit and Grayson takes him into an abandoned building.
When Nick wakes up, he decides that it is time to go on the offensive. He concludes that the best thing they can do is to go to Heathrow figuring that there must be some humans there. His thought is based on the fact that the pilot said that someone came through the radio and told him that there were problems with communication on a global scale and that they must continue as scheduled to Heathrow. Based on this, Nick thinks that maybe they were supposed to reach Heathrow but that something interfered with the original plan which eventually caused the crash. At Heathrow, they see plastic tents and helicopters between ruins. Nick and Grayson manage to sneak in and find suits worn by those who attacked them. They dress in those suits and then they investigate the tents, which prove to be labs doing experiments on humans and dissecting humans from the plane. Nick and Grayson are discovered so they decide to run by they are stopped by a familiar voice. When Nick turns around, he sees himself. The doppelganger Nick tells the real Nick that he is over one hundred years old and that Grayson’s father wants to see him. While Grayson discussed with his father, the future-Nick, Nicholas, tells the younger Nick what happened. After the main projects the Titan foundation wanted to accomplish became a reality, the group thought about something more ambitious. Sabrina played a crucial role in the new invention, a cure for death. Because of her, The Titans became immortal and began to grant the gift of immortality to those who were changing the world into something better. The problems began when Oliver Grayson wanted to make his son a Titan. Grayson suffered from liver cancer and because of his problems, he only had little time to live. The proposition was denied and Oliver and Nicholas decided to steal the cure. But the person they hired to steal it sold it to nations worldwide. Soon, a genetic mutation accrued and instead of making people immortal, the cure caused rapid aging. While the reason why the mutation happened was never discovered, the Titans theorized that maybe people started experimenting on the cure which eventually altered the original cure. After ten days when the cure was stolen, half of the population on earth died because of old age. Soon, the dying nations turned all their power against the Titans who were unaffected by the virus. Because of this, only thirty-eight people on the planet survived. Nicholas also tells Nick that they are the people who could save the human species and the reason why they brought them into the future is because they want Sabrina to develop a cure for the disease that will be used on the people who live on the space station. Those people will then try to repopulate the planet in time.
In order to make sure that the plan will succeed, Yul used the Q-Net he created to contact himself in the past. Yul from the future gave instructions based on which Yul contacted Sabrina and they made it so that some passengers received the antidote that was supposed to protect them from the virus. Then, they brought the plan into their time, thinking that in that way they will save themselves by making sure that the antidote works but will also prevent the same events taking place in the universe where Nick and Harper came from because Yul will no longer be there to create Q-net, Sabrina will not create the immortality serum and Nick will not become an associate with Oliver Grayson. Yul and Sabrina from the future however were concerned because they believed that taking people from the past and bringing them into the future could create problems. Because of this, they planned to send the passengers back into the past after they made sure that the vaccine worked. Oliver and Nicholas disagreed and thus the surviving Titans split which resulted into a civil war with Oliver and Nicholas controlling one side and Sabrina and Yul controlling the other side. Yul and Sabrina from the future died during the battle between the two groups of Titans and the rest of those who believed in them wanted to capture Yul and Sabrina and make Yul reconstruct the bridge so they could send the plane back into the past and let the future continue uninterrupted. Nick agrees to side with Nicholas, hoping that together they will be able to take down the Gibraltar dam, the place where Yul hid the device he used to bring the plane into their time and also the device that could send them back.
Meanwhile, Harper wakes up in a lab with Sabrina and Yul beside her. She slips in and out of consciousness and when she wakes up for good, she finds herself in a big room that resembles a hotel room. She realizes that she is at the Gibraltar dam and goes to investigate her surroundings. In one of the rooms, she finds Yul’s and Sabrina’s dead bodies placed on examination tables. Someone enters the room and Harper is shocked to see Sabrina and Yul alive and well. Sabrina tells Harper the same story that Nicholas told Nick but reveals why their flight was selected: it was because Oliver wanted to see his son and Nicholas wanted to have beside him the woman he loved, Harper. Sabrina also tells Harper that Nick, Nicholas and the rest will most likely attack the Dam in an attempt to destroy the only way they could return to their time. Harper is given the choice to side with Nick or with them and return home.
Harper returns to her room where she starts reading the novel she wrote, about a girl who received a letter from her future self. The novel was about a young girl who travels in the future to collect three artifacts that will eventually allow the owner to control time. But the main character in her book refuses to believe that the future is set in stone and Harper decide to believe that as well and decides to help Sabrina and Yul return the plane into the time they came from.
Harper goes and searches for Sabrina and Yul and finds them inside a lab. There, Sabrina tells Harper that the real reason why they were transported into the future was for Sabrina and Yul to find the truth about what will happen, find a way to maintain their memories and then return everyone to the past where they came from and prevent the tragedy that happened. Harper insists that she wants to be put into the machine that will give her the possibility of remembering what happened as well and also insists that if Nick wants to, they must give him the same chance.
Meanwhile, Nick, Nicholas, the Titans and some of the passengers they managed to save and are woken up are prepared for the upcoming battle. Nicholas tells the small group that if they see Sabrina or Yul, they are to shoot on sight as to prevent them from opening the bridge that will send everyone back into the past. Nick also mentions Harper and how she is innocent and that they must try and save her.
When Nick and the others reach the dam, they realize that the other Titans already brought colony back on earth the humans from the orbital in an attempt to stop Nick and the others from advancing. When the battle starts, Yul takes Harper into the residential area where he hides her in case the others manage to break in. He also tells Harper where the device is hidden in case he will be killed.
After a while, Nick finds Harper and though some questions Harper concludes that he is the Nick she meet on the plane. Harper tells him the real reason why Oliver and Nicholas brought the plane into their time and also that Sabrina and Yul figured out a method that will make them remember everything when they will return into their time. Realizing that Nicholas lied to him, Nick pressure Harper to tell her where he can find the device to send everyone back. Harper tells him and then together they go searching for the device. They encounter four Titans on their way there and Nick shoots them without blinking. For Harper, this is a sign that Nick is in fact Nicholas and that she must not let him get the quantum device. Harper lures Nicholas into an empty apartment and then she pushes him out of the window, Harper falling in the process as well into the water bellow, killing them both.
Meanwhile, the only survivors from Nicholas’s group are Nick, Mike, Grayson and Oliver. Oliver watches on a tablet the course Nicholas takes and a drone watches his moves. Because of this, they are able to see him and Harper fall into the water. Nick realizes then that something is wrong but it is already too late. Oliver sets the bombs off and shots Mike before running away with his son. Grayson tries to pray the tablet from his father’s hands and succeeds but he and Oliver fall on the ground and debris falls over them, killing them both. Nick manages to stop the bombs in time and then he is discovered by Sabrina who survived the attack. She tells Nick about her plans to maintain their memories and Nick insists that they should get Harper’s body and restore her memories as well even though Sabrina is not sure if it will work, given the fact that Harper died.
The third part takes place in the present from which Harper and Nick came from. However, not one of the people who were on the plane sent into the future remembers what happened. Nick accepts to invest in the dam at the Gibraltar and then agrees to invest into the Podway. Harper however, is unsure whether to accept the job of writing Oliver Grayson’s biography. Harper decides to work more on her Alice story and surprisingly, idea after idea starts flowing and the outline of the story is set.
Meanwhile, Nick meets with Yul and after the meeting, they both start having migraines. Nick meets with another person about the orbital colony project before he meets with Oliver for the first time. After the meeting with Oliver and Sabrina, Nick starts to have flashbacks and his migraines intensify. He returns to his hotel room where he remembers bits and pieces of what happened in the future and decides to return to London, figuring it out that Harper is the last missing piece.
When Nick reaches her apartment, he remembers her and what they went through. What is more, Harper remembers him as well and they spend the night together. The next day, Harper decides to focus on Alice and follow her dream while Nick talks with Oliver about including Oliver’s son into the foundation as well and Grayson not only becomes happier, but he also brings some ideas of his own.
The novel ends with Harper and Nick inside Harper’s apartment thinking about the future and about the things they will accomplish together.