High conflict divorce can leave children polarized within the transitioning family system, aligned with one parent and resisting or refusing contact with the other parent. Rather than becoming mired in the bottomless pit of back and forth blame, more and more courts are seeking remedies in the form of reunification therapy. Charged with helping the polarized child to enjoy a healthy relationship with both parents, we know what doesn't work: individual child therapy cannot remedy a family systems problem. Dyadic interventions with the child and either parent are seldom sufficient. Even family therapies fall short when they are not grounded in well-established, reliable and valid science. Mending Fences introduces a child-centered, systemically informed, empirically-validated and experientially-proven collaborative reunification protocol. Focusing on the anxiety inhibiting the system's healthy functioning, well-respected and long-validated cognitive behavioral exposure methods are fused with structural family therapy to reduce the child's anxieties about separating from one parent and approaching the other, the aligned parent's fears of separation and loss, and the rejected parent's fears of rejection. A common vocabulary across coordinated interventions allows children across the spectrum of ages and abilities to identify and overcome an individually tailored succession of anxiety-inducing events so as to gradually (re-)establish healthy and safe relationships with both parents. The Mending Fences protocol is practical, proven, and effective. Case illustrations, sample court orders and service agreements are included. The user-friendly discussion is peppered with up-to-date references to the scientific literature and international case law. Application via video conferencing platforms is discussed.