After a devastating alien invasion devastates Earth in successive waves, a teenage girl fights to survive and find her brother. The 5th Wave (2016) is a YA dystopian sci-fi thriller, mixing alien invasion spectacle, survivalist action, and young adult romance in a post-apocalyptic setting.

Från IMDB:
Four waves of increasingly deadly alien attacks have left most of Earth in ruin. Cassie is on the run, desperately trying to save her younger brother.