1900: Anna Bradley spends summer days supervising three little girls, including her niece, Julia Demarest, on an island off the coast of Haven Point, Maine. Inspired by the summer antics of Julia and her friends, Anna writes Liberty Island --- a depiction of girls unshackled from the domestic sphere --- under a pen name. It’s a runaway bestseller, but it’s not well received by the society matrons in her sister’s circle, who believe that books for girls should prepare them for their future as wives and mothers. 1922: As new, bohemian ideas take hold amongst her peers, Julia Demarest has come to see her aunt’s Liberty Island books as quaint at best. When her mother urgently calls her back to Haven Point, Julia is confronted by all the things she's been trying to escape and forced to reconsider what truly brings her happiness.

In 1944, Maren Larsen is determined to do her part to help the war effort. As a cadet nurse at Walter Reed Medical Center, she’s swept off her feet by Dr. Oliver Demarest, whose family spends summers in an insular community on the rocky coast of Maine. In 1970, as the nation grapples with the ongoing conflict in Vietnam, Oliver and Maren are grappling with their fiercely independent 17-year-old daughter, Annie, who has fallen for a young man they don’t approve of. Before the summer is over, a terrible tragedy will strike the Demarests --- and in the aftermath, Annie vows never to return to Haven Point. In 2008, Annie’s daughter, Skye, has arrived in Maine to help scatter her mother’s ashes. Maren knows that Annie never told Skye the whole truth about what happened during that fateful summer.