Saeed and Nadia are young adults living in an unnamed city on the brink of war. Saeed asks Nadia to coffee, and they begin to date. However, between societal rules restricting men and women being in public together and escalating tension between the government and a militant group, they rarely get to see each other. Because Saeed lives with his parents, he sometimes goes to Nadia’s flat, disguising himself as a woman to not cause a scandal. Otherwise, they text frequently. Then, the government cuts off all cellular and Wi-Fi service as a counterterrorism measure, which also cuts Saeed and Nadia off from each other. Saeed searches everywhere for Nadia and finally waits all day at her flat for her to return. He begs her to move in with him and his parents, but Nadia is reluctant. When Saeed’s mother gets killed by stray gunfire, Nadia relents and moves in with Saeed and his father. As the fighting worsens, Saeed and Nadia hear rumors about magical doors that can transport people anywhere in the world. They don’t believe these rumors.
The militants eventually take the city, imposing strict rules and surveillance. They hold public executions of those who break their religious rules and those who belong to certain religious denominations. Desperate to escape, Saeed and Nadia meet with a man who agrees to secure them passage out of the city via a magical door. He takes their money and agrees to get in contact. When they hear from him again, Saeed’s father announces he will not go with them. He makes Nadia promise to stay with Saeed until Saeed is safe and settled. The next day, Saeed and Nadia pack small backpacks full of supplies and meet the mysterious man at the rendezvous point. He sends them through a door. They emerge on the island of Mykonos, where a large refugee camp has grown. Wealthy countries have also discovered these doors and keep them strictly guarded to try and cut back on the number of refugees in their countries. After a few months, Nadia befriends a local girl who promises to help them leave Mykonos. The girl makes good on her promise and sneaks Saeed and Nadia through a newly discovered door.
They emerge in an empty mansion in London and stay in one of the rooms. Other refugees come to live in the house alongside them. Saeed and Nadia start to feel less in love and become more irritated with each other because of the stress of their ordeal. Some London citizens attack refugees, but others volunteer to bring food and medicine into the occupied houses. The British government cuts the power to the neighborhood. As more refugees enter London, they divide themselves by national origin. Saeed would like to move to another house to be closer to others from their country, but Nadia prefers to stay where they are. Eventually, the British government begins a push to make the migrants leave the houses they’ve occupied. There is a violent siege, but the government finally relents. The government plans to build a halo city on London’s outskirts for the migrants to live in. Saeed and Nadia move to a work camp and build houses so that they can someday earn a forty-meter house of their own. Between exhaustion and their fizzling romance, they fall into a rut. Nadia suggests they move to Marin in California.
Nadia and Saeed set up a shanty house in Marin. Nadia starts working at a co-op, and Saeed finds solace in a Black-majority religious congregation. Even though they both settle into their new lives, they find themselves changing. Nadia begins to realize that she’s bisexual, and Saeed becomes attracted to the daughter of the preacher at his congregation. Although they still enjoy each other’s company, they begin to feel more like friends than lovers. They don’t want their relationship to sour, and they know they have to separate. One day, Nadia simply packs her things and leaves. She moves into a room at the co-op where she works and later starts dating one of her coworkers. Saeed grows closer to the preacher’s daughter, and they start dating. Although their separation is difficult at first, Saeed and Nadia eventually fall out of touch. Fifty years later, they meet again in a café in the city they once fled from together. Saeed talks about the stars in the Chilean desert and offers to take Nadia someday. They leave not knowing if they’ll ever see each other again.