This article reviews evidence from developmental, clinical, and psychotherapy process literature about storying emotional experience as a pathway toward change for clients with complex posttraumatic stress. Capacities for emotion regulation, mentalizing, and autobiographical memory storytelling emerge in childhood relationships (Cassidy, 1994; Fonagy, Steele, Steele, Moran, & Higgitt, 1991; Nelson, 1993). Developmental disruption of these capacities in the context of childhood trauma (e.g., Pears & Fisher, 2005) may contribute to adult complex posttraumatic stress (Cloitre, Miranda, Stovall-McClough, & Han, 2005; van der Kolk et al., 2001). In particular, survivors may have difficulty engaging adaptive metacognition (Lysaker et al., 2015) to regulate emotions (Paivio & Angus, 2017) evoked by explicit and implicit trauma memories. Difficulty integrating emotional experience into a coherent narrative poses a challenge for psychotherapy engagement (Angus & Greenberg, 2011). It also represents a potent area for change, as the empathically attuned, responsive therapist can help clients develop a “storytelling function” for a more emotionally integrated, coherent understanding of the self and relationships (Holmes, 2001). The Narrative-Emotion Process (N-EP) model (Angus, 2012) is an integrative process-guiding framework to facilitate adult clients’ capacities to reflect on and story emotional experience. First, we summarize research on the development of emotion regulation, mentalizing, and autobiographical narrative capacities in the context of childhood relationships. Second, we review complex posttraumatic stress sequelae through the lens of disrupted narrative-emotion processing. Finally, we present the N-EP model and recommendations for process-guiding interventions that promote narrative-emotion integration in the treatment of complex posttraumatic stress in adults, illustrated by emotion-focused therapy case material.