We Were Liars by E. Lockhart

Cadence, a member of a wealthy yet broken old-money East Coast family, spends each summer on her grandfather's private island. Life isn't perfect no matter how hard the family tries to make it seem.

That's about all I can write without giving too much of the plot away.

I raced through this book in a day, but was actually left feeling unsatisfied. Everything seemed a bit thin.

A so-so fast read. I think you can do better.