Every summer for generations, three families intertwined by history, marriage, and career have spent "the season" at their beach cottage compounds on an island in Puget Sound. Today, Martha "Pete" Petersen, married to Tyler Strong, is the lynchpin of the "summer people." In childhood, she was the tomboy every girl wanted to emulate and is now the mother everyone admires.

Colin Ryan, family friend and the island's veterinarian, met Pete first in London, years earlier, when she visited his roommate, Tyler. He's loved her ever since. Born in Manhattan's Hell's Kitchen, son of a bar owner, he's always been dazzled by what he sees of the sun-kissed lives of the summer people.

But this summer, currents strong as the tides roil: jealousies grow, tempers flare, passions clash. Then, on the last day of the season, a series of betrayals alters the combined histories of these families forever.