Hannah Sullivan is not looking to have her beliefs challenged. She is not looking to fall in love, either. Her only ambition, when she and her daughter, Lily, take their first summer trip to New Hampshire’s Squam Lake, is a restful, scenic vacation. But she will soon learn that the world has another offering. Within minutes of their arrival that first summer, they meet a man named Aidan Heron. His is a gift that will teach them both, with an easy humor and a nearly fearless penchant for adventure, that life has more to offer than they'd ever understood. Shaped by tragedy in her youth, Hannah has learned to live a timid, closed life. And without realizing it, she has taught her daughter to do the same. But Aidan, a man who has experienced his own tragedy and responded very differently, will show them both a new way. Through ten years of shared summer vacations, Hannah will experience enthrallment, love and heartache. She will be challenged and will learn to challenge herself. And in the course of meeting these challenges, she will learn how to truly live.