Sometime in the future, Elizabeth 'Daisy' Rybeck, an irritable, neurotic American teenager, is sent by her father David to the English countryside for the summer to stay with her Aunt Penn and her three cousins: Eddie, Isaac, and Piper. Daisy arrives at
Heathrow Airport to tightened security and reports of a bombing in Paris and is greeted by Isaac, who drives her to their farm. Daisy remains abrasive towards her cousins and their neighbour's son, Joe. She learns from her aunt that her late mother Julia, who died in childbirth, also used to stay at the farm frequently. Shortly after her arrival, Aunt Penn flies to
Geneva to attend an emergency conference because she is an expert in terrorist extremist groups. Meanwhile, Daisy begins falling in love with her eldest cousin, Eddie. The children's summer fun ends when
terrorists detonate a nuclear bomb in London that kills tens of thousands. Soon the electricity goes out and they learn from an emergency radio broadcast that
martial law has been imposed. An American consular official offers Daisy safe passage home but she decides to stay, set upon her love for Eddie. Later on, a group of soldiers attack their home and forcibly separate the boys and girls, who are to be evacuated to separate parts of the country. Eddie tries to fight back but is pinned down by the soldiers. He calls for Daisy to return to the farm whenever she can. Daisy and Piper are fostered in the home of a military officer and his wife and assigned to work on a farm. When the area is attacked by terrorists, Joe, who is working on the same farm, is killed. The two girls escape to the countryside and begin a days-long walk back to their home. Daisy witnesses the mistreatment of captives and later the aftermath of a massacre near the camp where Isaac and Eddie were taken. She does not find Eddie among the dead, but she does find Isaac's body. She mournfully takes his glasses and buries them. Two armed men chase the girls through the woods, but Daisy shoots them both and the girls flee. Later, the girls are on the verge of giving up when they see Eddie's pet hawk fly overhead and follow it back home. They discover that the military troops stationed there have been massacred and the house is empty. Only their dog remains. The next morning, Daisy follows the dog into the woods, where she finds Eddie lying unconscious, his face and hands scarred and his eyes swollen shut. In the aftermath of the war, Daisy nurses Eddie. A
ceasefire is announced, electricity is restored, a new government forms, and the country begins to recover. Sometime later, Eddie is mute and has
post-traumatic stress disorder. Daisy promises to be there for him, hoping that he will recover. ==Cast==