Okwe, a doctor in his home country (not initially named) who was forced to flee after being falsely accused of murdering his wife, lives in the United Kingdom as an undocumented immigrant. He drives a cab in London during the day and works at the front desk of a hotel at night, which is staffed by other immigrants, both documented and undocumented. He is pressed into giving medical treatment to other poor immigrants, including fellow cab drivers with venereal diseases. He is supplied with antibiotics by his friend Guo Yi, an employee at a hospital mortuary.
Juliette, a sex worker who regularly conducts her business at the hotel, informs Okwe about a blocked toilet in one of the rooms, and he fishes out a human heart. The manager of the hotel, Juan, runs an illegal operation at the hotel wherein immigrants swap kidneys for forged passports. After learning of Okwe's past as a doctor, Juan pressures him to join his operation as a surgeon, but Okwe refuses.
Senay is a Turkish Muslim seeking asylum who also works at the hotel as a cleaner. Her immigration status allows her to stay in the UK, provided she does not work; the hotel is a perfect cover because she is not named on its books. She allows Okwe to sleep on her sofa when she is not home, as she is from a conservative culture where men and women who are not married do not spend the night together under the same roof. After Senay is visited by Immigration Services, who inspect the hotel after finding a book of matches in her flat, Okwe prevents the officials from intercepting her.
No longer able to work at the hotel, Senay begins working in a sweatshop making clothes, which is also raided by officials looking for undocumented immigrants, who the manager gets rid of. The manager allows Senay to keep her job and not report her to the authorities in return for her performing oral sex on him; she initially complies before proceeding to bite him. Okwe finds her a place to stay at the hospital mortuary, while Senay asks him to accept Juan's proposition in his organ business to raise money to travel to America.
In desperation, Senay offers her kidney to Juan for a passport; Juan accepts the deal on condition he takes her virginity as well. Senay is later provided with a morning-after pill by Juliette. After learning of Senay's plan, Okwe agrees to perform the operation to ensure her safety, but only if Juan provides them both with passports under different names. After Juan delivers the passports, Okwe and Senay drug him, surgically remove his kidney, and sell it to Juan's contact.
Okwe plans to use his new identity to return to his young daughter in Nigeria, and Senay plans to start a new life in New York. Before they part at Stansted Airport, they mouth the words "I love you" to each other, and she gives him her cousin's address in New York. Senay boards her plane, and Okwe calls his daughter long-distance to tell her he is finally coming home.
