Dear Nadia,

What's that old expression, "Home is where the heart is"? I'm more inclined to believe Robert Frost: "Home is where, when you have to go there, they have to let you in." And that seems to be the guiding principle behind your new film How I Live Now. On the surface, it's a survival story set during the outbreak of a third World War. But really, that's just the window dressing for a good old fashion coming-of-age tale. One that centers on a teenage girl finding her place in the world - literally, and figuratively. Though it's not always successful.

Let's start with the literal part, since that's obviously your cup of tea.

Saoirse Ronan plays Daisy, an American girl who is shipped off to stay with her relatives in the U.K. She lives in her own head, doing her best to block out the world with headphones clamped to her ears and a constant "piss-off" disposition. Director Kevin Macdonald tries to get us into Daisy's unruly headspace with rapid-fire overlapping voiceovers and the moody rock of Amanda Fucking Palmer. As Daisy reluctantly makes her way through higher-than-normal airport security, she eventually gets to a serene house in the countryside. Of course, she can't see the beauty in her new home, though it's seductively shot on grainy film stock with deeply saturated colours. So she mopes around as her cousins swim and swing in blissful ignorance of the imploding world at large.

Once the bombs go off and ash blankets what should be her newfound paradise, it's not long before soldiers follow and the story makes a dramatic shift. Suddenly the idea of "home" takes on a much different meaning, and finding it again becomes more of an emotional journey than a physical one.

Despite looking quite good, however, this adaptation of the award-winning young-adult novel by Meg Rosoff feels like it's missing a few too many furnishings to be comfortable with itself. The characters, for one, amount to little more than their stock personas; nerdy cousin with glasses (Tom Holland), needy cousin with red hair (Harley Bird), handsome cousin to get naughty with (George Mackay). Moreover, the approach to genre is as confused as an angst-ridden adolescent, swinging wildly between moods and styles. The first few minutes of the film feel like an upbeat 70s rock 'n roll film, before shifting into a European domestic drama, then an American summer camp movie, then a grim guerilla warfare film, and so on. By the time it all ended, I couldn't really figure out who it was trying to please or where it really wanted to go. I certainly didn't feel like I ended up in the same place as the people I followed. Figuratively, anyway.

It's that tension proves to be How I Live Now's biggest problem. It's the characters we want to be constantly searching: the filmmakers need to settle somewhere and call it home.

Shouldn't you have helped them with that?