There are two kinds of people on the island - those who leave at summer's end...and those who are left behind.

For 17-year-old Winnie, summer can't arrive fast enough - anything to get out of the house and escape the cold war brewing between her parents. With her older sister, Shelby, spending the summer in Boston, Winnie's left to deal with the situation all by herself. Which is why she's happy to spend all day away from home at a cushy job - camp counselor at the prestigious Oceanview Inn.

And when the Barclays, a wealthy summer family, offer Winnie an additional babysitting job in the evenings after work, she jumps at the opportunity. Little Cassie Barclay is fun to take care of, and hanging out in the gorgeous Barclay summer house overlooking the harbor is far more pleasant than being on the front lines of the battle between her parents.

Then Cassie's older and devastatingly attractive stepbrother, Jay, arrives on the island after a disastrous first year at college, and he seems to want nothing more than to wreak havoc for his stepmother and the rest of his family. Winnie soon discovers that life in the Barclay summer house isn't so perfect after all, and what was supposed to be a carefree summer escapade is quickly becoming more complicated than she ever thought possible....