In the dry heat of her Arizona home, feisty, Irish-Catholic Colleen Moretti, thrusts the letter that threatens her marriage into the back of a drawer. This is her default mode: ignore the fault lines until the tremors pass. But her husband Derek's faithlessness turns out to be far worse than Colleen initially suspects. With two daughters caught in the middle of a crumbling marriage, one who would love to see her father cut out of their lives and the other who would be crushed to lose him, Colleen is trapped in a no-win situation. This complex story of a family unraveling is told from the alternating perspectives of Colleen and her college-age daughter, Rachel, both of whom struggle to maintain their balance amidst feelings of love and loss, anger and betrayal. A gifted cellist, Rachel escapes into her music and her campus life, including her burgeoning romance with her first real boyfriend. But her coming of age tale is fraught with complications from what's happening in her family home, where in her desperation to sustain hope, Colleen turns a blind eye to Rachel's struggles. Instead, Colleen clutches onto her faith that preaches forgiveness and to the tender memories that preserve her image of the husband and father she has known Derek to be. Mixed in this soup is eight-year-old Izzy, whom both Colleen and Rachel try to protect from the fallout of this family drama. Once You Know is the story of one mother's desperate attempt to reweave the bonds of family. This tense, emotional women's fiction novel traces Colleen's journey as she comes to grips with an impossible situation. Perhaps most painful of all, Colleen must confront her own hand in what transpired. Trigger warning: This novel is set against the backdrop of the Me Too movement and contains references to sexual assault that may be disturbing to sensitive readers.