In 2027, the world is in chaos after 18 years of global human infertility. Society has collapsed, countries have closed their borders, and the United Kingdom stands as one of the last functioning governments, albeit a totalitarian one. Amidst this dystopian landscape, the British populace is plagued by despair and violence, with the government imposing oppressive laws against immigrants, who are detained in ghettos and refugee camps. Amid the turmoil, Theo, a disillusioned bureaucrat, leads a life marked by grief for his lost child and estrangement from his activist wife.

Theo's life takes a dramatic turn when he is abducted by the Fishes, a rebel group fighting against the government's brutal policies. He is reunited with Julian, his estranged wife, who reveals a miraculous secret: a young refugee named Kee is pregnant, the first known case of childbirth in nearly two decades. Julian entrusts Theo with the mission of transporting Kee to a sanctuary at sea, believed to be run by a group called The Human Project, which offers hope for the future. As they embark on a perilous journey through a society falling apart at the seams, they must navigate through dangerous territories, elude capture by both the government and rebel factions, and confront betrayal and treachery. The fate of humanity hinges on the protection and delivery of Kee and her unborn child to a safe haven, making their journey not just a fight for survival, but a quest for hope amidst despair.