Daisy (Saoirse Ronan) is an American teenage loner with an attitude problem. She's been sent to stay with her aunt (Anna Chancellor), a government peace negotiator, and her three children at their home in the English countryside.

They live the sort of carefree, bohemian Guardian-reader lifestyle that is the antithesis of what urban Daisy considers to be cool. But just as she is starting to warm to the rural existence, and one of her cousins, a nuclear bomb hits London and they are forced to go into survival mode when official forces try to destroy their idyll.

It manages to successfully tread the fine line between coming-of-age romance and post-apocalyptic thriller/road movie that manages to appeal to its target age group as well as to adults by not holding back on the realities and chaos of a country at war, with some scenes deserving the film's 15 rating.

It is bleak at times, which could explain why it didn't do as well in cinemas as it should, but it is a fine example of the PA genre because of its plausibility that does not rely on sensationalism or CGI effects to convey the story.

How I Live Now is out on DVD and Blu-ray on February 10.

To celebrate the home entertainment release we have a fantastic competition with three film merchandise gift packs (above), including a copy of the DVD. Click on the link below to enter the competition.