Didn't know quite what to expect from this but was quickly captivated by this film. Saoirse Ronan gives a superb performance and really holds the film together. Initially its a fish out of water story about Saoirse Ronan's character, a difficult but intriguing American teen landing into an eccentric English rural family who live on a remote farm. She quickly starts to fall for her handsome cousin but then world events intervene as a nuclear device is detonated in London and the film shows them dealing with the new reality of soldiers at the door, mass evacuation and the family being split up. The depiction of what UK would be like under martial law, with guerrilla attacks, forced labor camps and a society breaking down was both chilling and fascinating. Ultimately, it becomes a survival story as Saoirse Ronan's character tries to get back to the farm and she has to make her way through the nightmarish landscape of an England descending into chaos. With a great soundtrack and many poignant moments, this is a well crafted film on all fronts. Recommended.