A daughter's unflinching exploration of the intimate and unconventional relationship she shared with her mother--a brilliant, charismatic woman haunted by a traumatic past. When Leah is eight, her mother, Cessie, abruptly flees her role as a rural housewife in search of a glamorous career in the city. In the chaotic years that follow, Cessie lurches from one apartment, job, and toxic romance to the next. In a home without rules or emotional boundaries, daughter and mother become close confidantes--a state of enmeshment that suits them both. Their bond is loving but also marked by casual indifference. Cessie's self-described parenting style of "benign neglect" is a hilarious party joke, but for her daughter it's reality. In Leah's first year of high school, her mother makes a disclosure that will forever alter their relationship: She confides that from the age of 12 well into her teens, she was the lover of her 45-year-old married pony club instructor. The trauma of the "Horseman," Cessie explains, is not just a dark family secret but the reason for all her ill-conceived life choices, including marriage and motherhood itself. For years after, into adulthood, Leah is haunted by the specter of the Horseman. He is the nameless anxiety and restlessness she observes in her mother and increasingly recognizes in herself. Eventually, she and Cessie set out to discover truth of what became of her mother's rapist. The investigation that ensues pushes their relationship to the brink of collapse. Leah is seeking solace in the facts, but first she must confront a deeper, more painful truth: that her story--the story of trying and failing to love a complicated mother--is not the Horseman's after all. A riveting and devastating portrait of mother and daughter, Where You End and I Begin is a memoir that explores how trauma is shared between women and how acts of harm can be confused with acts of love.