It follows the story of two brothers and their girlfriends, journeying across the country after a world-ending pandemic. Not the zombie kind of outbreak, just some horrible 100% fatal virus. Most everyone is dead and the brothers are planning on heading to an old family vacation stuff on the beach to wait things out.
The movie isn't an action movie or a horror movie; more a suspense/thriller. The journey doesn't go as planned and the group has to deal with the complications along the way: What to do about the father and his sick daughter they meet on the road? Leave them, kill them and take their stuff, bring them with at the risk of getting infected? Tough, bleak decisions. It's not a cheery movie, that's for sure.
Overall, pretty decent movie, if a bit serious, depressing and a little slow. I prefer a bit more fun or action in my end of the world movies (Road Warrior, Book of Eli, Red Dawn), so I probably won't watch this again and wouldn't give it a "buy" recommendation. It's certainly worth a free view on Netflix. Oh, and it's only PG-13, so expect less violence, language and so-on than the typical fare.