Brianna hasn't been back to the island in ten years-not since her summers with Grandma ended so abruptly. When an unfortunate situation arises across the water, Brianna's busy mother turns to her for help. Brianna half-heartedly agrees, expecting it'll be no time before she's back to the sweet, easy summer days spent with her two best friends, drifting between life after high school and before whatever came next. Instead, the island draws her in. Through new friendships, old memories, and unexpected discoveries, Brianna begins to uncover a life she never knew she wanted. But her return stirs something else, too-questions about why her mother has stayed away for a decade, and what really happened all those summers ago. Brianna isn't the only one carrying curiosity over the past. Cheryl is forced to confront memories she has spent years avoiding. Mara is grieving while trying to hold together a life that is quietly changing. And Oliver, content to drift through island life without much of a plan, finds himself suddenly facing a future he never expected. Four lives. One island-and that island holds more than past memories. It offers discoveries in more than one way and new beginnings waiting on The Other Side.