Saoirse Ronan plays Daisy, an American girl visiting her family in England, although she may have been forced to go by her father. At first she is supremely hostile towards her younger cousins (Tom Holland, Harley Bird), while doing a very bad job of being intimidated by the brooding handsomeness of her older cousin Eddie (George McKay). Over the next few weeks, she begins to let her guard down and have a genuinely good time, and the movie seems set to take the course of every other "that one great summer that I will never forget" type of movie. And that's when the movie drops its bombshell, literally. A nuclear device goes off in London, the army come to the secluded farmhouse where they’ve been staying, and send the boys and girls off to separate housing sites. From there, Daisy resolves to reunite the family again, no matter what.

There are so many movies that come to mind while watching How I Live Now; the unexplained dystopia from Children Of Men, the seemingly endless march of struggle from The Road, the confined focus of a mass event from Right At Your Door, and the kids fighting back against the army from Red Dawn and Tomorrow When The War Began. What makes this movie stand out is that while it focuses on a group of teenagers and young kids, it never shies away from some of the more grim aspects of the situation that they’ve been put into. They’ve also got a stand-out performance from Ronan who helps anchor some of the nastier moments both of the film and her own, initially unlikeable character.

Director Kevin McDonald (The Last King Of Scotland, State Of Play) does a great job of using little moments to express a grander scale, such as during the initial nuclear attack when all we see is a strong wind and ash falling like snow. There are some moments that feel a little forced (the speed at which a love story develops would put the Enterprise to shame), and others that are more than a little unsettling (incest, rape, murder, mass executions and more rear their nasty heads at one point or another), but even these issues help feed into the unique nature of How I Live Now, and ultimately what makes it a difficult, somber, emotional and fantastically acted film.