The only appropriate time to fantasize about your entire family's death is during puberty. Teen fantasies are consumed with romantic, melodramatic catastrophes: car accidents, shipwrecks, kidnappings, all starring the teens themselves and perhaps a mysterious love interest. Few films present this beautiful complexity of a newly formed adult brain hopped up on hormones, yet still filtering the world through the experiences of a child, better than How I Live Now.

Daisy is an American teen (played by Saoirse Ronan) who's sent to stay with distant relatives in the English countryside. She resents it. The bitchy New Yorker is pin-thin, heavily made-up, and needlessly strict about germs and food in the way of a young woman trying to control her emotions through her environment. Slowly Daisy warms to farm life with the help of her cousins, 14-year-old Isaac (Tom Holland), his younger sister Piper (Harley Bird), and Edmond (George MacKay), the eldest sibling and Daisy's burgeoning love interest. They swim, they picnic, Daisy falls in love.

Then a nuclear air strike hits London. Ash rains from the sky, signaling the start of World War III.

"I am a fucking curse," Daisy moans after the air strike, in the way that only teenagers can manipulate a national disaster to reflect their own importance. Within days, troops descend and forcibly separate the cousins by gender, who vow to reunite at the farm. The first half of How I Live Now is shot through a golden lens of idyllic youth; the second half is a thrillingly grim coming-of-age story. Daisy's earnest escape plot hasn't prepared her for the realities of a war-torn country, and it becomes increasingly clear that even as she pushes Piper on a death march towards home, there's no guarantee what, or who, they'll find when they return. Even if you dislike war films, the superior child acting in How I Live Now makes it riveting, emotional, and well worth a few tasteful corpse shots. recommended