Megan Mazeros and Lauren Mabrey are complete opposites on paper. Megan is a girl from a modest Midwest background, and Lauren is the daughter of a senator from an esteemed New England family. But in 1999, Megan and Lauren become college roommates and they forge a strong friendship. The summer before their senior year, Megan joins Lauren and her family on their private island off the coast of Maine. Late one night at the end of the vacation, something unspeakable happens, searing through the framework of the girls' friendship and tearing them apart. Many years later, in the midst of a political scandal, Megan finally comes forward about what happened that fateful night, revealing a horrible truth about Lauren's family and threatening to expose their long-buried secrets.