An ordinary British family contends with the hopes, anxieties and joys of an uncertain future in this six-part limited series that begins in 2019 and propels the characters 15 years forward into an unstable world. Daniel (the youngest brother) is getting married to Ralph, Stephen (the oldest brother) and Celeste (his wife) worry about their two daughters, Edith (the oldest sister) is engaged in one humanitarian cause after another, and Rosie (the youngest sister) is a single mother with spina bifida raising one boy, and about to give birth to a second son, Lincoln. Presiding over them is Gran, the imperious Muriel.
In 2028, extensive flooding and two dirty bombs result in large numbers of displaced residents in the UK. Checkpoints are erected around Rosie's estate in Manchester in response to criminal activity in the area. Bethany is fitted with a brain implant which enables her to interact directly with the internet, but also to spy on her family. Muriel is diagnosed with macular degeneration but is able to pay £10,000 for fast-track NHS surgery which reverses the condition. Stephen blames Viktor for Daniel's death. He also starts a new job with Woody, an old school friend. At a business auction held at Chequers, he encounters Viv Rook by chance before his company wins the contract to maintain two of the new "Erstwhile" concentration camps. Watched by Bethany, Stephen uses the company's computer system to send Viktor to the camp.