As a spirited nine-year-old child, Kai Martin sees her life as a series of concentric circles—her twin brother and other half, Kade, occupying the center sphere with her, their loving parents surrounding them in the next, and the Tyler family in the outer loop. Their families have been linked since before she was born, and she plans to make that connection official someday by marrying Josh Tyler. The Tylers and Martins share many good times, but under the surface, they are two dysfunctional families struggling with alcoholism, depression, and abuse, all of which Kai becomes increasingly aware as she grows up. Her circles become less and less stable, until a great tragedy knocks her completely off her axis, no longer sure of anything.

Years later, Kai and Josh reconnect as young adults, falling in love and embarking on a life of travel and adventure, building on their shared history, yet also haunted by it. They share a deep connection, but as time goes on, Kai sacrifices more and more of herself to hold on to Josh, the one thing left in her life of which she thinks she can be certain. Eventually, though, she learns that she herself is precisely the one thing that she can trust, and that she is whole and complete all on her own.

ALL I KNOW is about loss and resilience, rising from devastation to build and rebuild a life, over and over again. The story explores the heartbreaking truth that as much as we try to help and hold onto the people we love, we can only truly save ourselves.