American teenager Daisy (Saoirse Ronan) has attitude to burn. Her mother died giving birth to her, her dad has sent her away for the summer to live with her aunt and cousins in the English countryside. Defiant and unhappy, city girl Daisy refuses at first to warm to her bucolic new surroundings or the three cousins she’s meeting for the first time: 17-year-old Eddie (George MacKay), 14-year-old Isaac (Tom Holland) and 8-year-old Piper (Harley Bird). But although it looks to be crumbling around them, her cousins’ farm, Brackendale, is an enchanted place. With their mum (Anna Chancellor) engrossed in her role as a peace negotiator, they have the run of this romantic bohemian idyll to themselves along with their friend Joe (Danny McEvoy), two dogs and a goat. Slowly, Daisy begins to thaw. Plus, there’s something about her quiet, watchful older cousin that not only intrigues Daisy, but stirs something deep inside. Before she knows it, she’s falling madly in love with Eddie, and he with her… Their perfect summer is blown apart by the sudden outbreak of a 21st century world war, leaving them isolated and forced to fend for themselves. When they are violently separated Daisy must embark on a terrifying journey in order to be reunited with the boy she loves. Eddie is never far from Daisy’s mind but as her journey to find him becomes more desperate, the idea of what she may or may not find consumes her consciousness and haunts her soul.