Saoirse RonanRobin Marchant/Getty

A teen struggling to survive in the dystopian future -- no, we're not talking about "The Hunger Games," but rather "How I Live Now," an adaptation of Meg Rosoff's popular novel.

The movie's new trailer shows an American teen named Daisy ("Hanna" star Saoirse Ronan) moving to the English countryside when World War III breaks out.

"Before the war, I thought one day the world around me would start to make sense," she says.

Once there, she falls for the handsome Edmond (George MacKay) and they enjoy an idyllic summer, until the bomb drops -- literally. Then soldiers come to take them away, separating the young lovers.

"Wherever they take you, find a way to get back here," Edmond pleads. When Daisy manages to escape her camp, she embarks on a dangerous journey to return home.

How I Live Now- Trailer No. 1
"How I Live Now" also stars Tom Holland and Anna Chancellor, and opens October 4 in the U.K. and later this fall in the United States.
Stephenie Meyer and Saoirse Ronan on