This novel follows the lives of two friends, a working-class Englishman and a Bangladeshi Muslim, living in London. The story explores the complex relationships between people of different races, cultures, and generations in modern Britain, with themes of identity, immigration, and the cultural and social changes that have shaped the country. The narrative is enriched by the characters' personal histories and the historical events that have shaped their lives.

The novel centers around a woman named Amber who unexpectedly arrives and disrupts the lives of the Smart family while they are on summer holiday in Norfolk. Each family member - Eve, a writer, Michael, a university professor, and their children Astrid and Magnus - experience unique interactions with Amber, causing them to question their own realities. The mysterious woman's influence forces the family to confront their secrets, insecurities, and the false narratives they've created about themselves.

The book centers around a curmudgeonly widower whose strict routines and grumpy demeanor hide a deep sadness after the loss of his wife. His solitary existence is disrupted when a boisterous young family moves in next door, leading to a series of comedic and heartwarming events that gradually thaw his icy exterior. Through these interactions, the protagonist's past is revealed, and he forms unexpected friendships that give him a new lease on life, showing that even the most steadfast loner can find community and purpose when least expected.

The novel follows the life of a 39-year-old single, childfree woman living in New York City who is dealing with the societal pressures and expectations of adulthood. Her journey is marked by her struggle to find happiness and fulfillment in her own terms, despite her unconventional lifestyle. The protagonist grapples with her relationships, career, and the looming presence of her family's tragedies, all while trying to understand what it truly means to be "all grown up".