The Beach House tells the tale of an 18 - year - old girl named Rosie, who struggles with change and adores her family. The highlight of her year is when she makes her annual trip down to her grandfather's beach house in a remote town in California for the summer. This particular summer was similar to all the others, as it quickly offered her the same joys it always did. However, when crisis strikes and Rosie's extended family invades her second home, things begin to slowly fall apart. As family turns foe, Rosie is forced to wonder who she can really trust.