ER doctor Sloane Marks is shattered when she learns her husband Ethan slept with his partner at Seattle Homicide. She considers leaving him and joining The One, having gone to college with the popular dating app's billionaire founder, Brody Carr. But at forty-two, Sloane feels she has no choice but to forgive Ethan if she wants a chance at creating the family she never had.

Months later, Sloane bumps into Brody, who's recently returned to Seattle. In due time, Ethan worries she's cheating. His suspicions are confirmed when he learns the rich app founder took Sloane on a freediving excursion in the San Juan Islands. Soon after, Brody's famous wife dies in an accident. Ethan becomes the lead investigator in her death, which he suspects wasn't at accident at all.

Caught between a distrusting husband and a powerful billionaire who protects his secrets at all costs, Sloane is in a fight for her life. And the only way out is to take matters into her own hands.