The authors describe significant turning points immanent in "never again" stories that practicing nurses, having participated in previously, vowed not to allow to recur during future, similar situations. Nurses submitted written accounts of critical, "never again" situations. The authors used critical incident technique and employed Colaizzi's approach to reveal the essential structure. Patient outcomes were fatal, close calls, dehumanizing, or isolating. Never again stories incorporated ethical dilemmas, deficits in nurses' knowledge, lack of confidence in clinical abilities, and failure to act correctly. Patients' welfare was the center of accounts. Circumstances threatened patients' and family members' trust in nurses and other providers. Patients' wishes were denied because of haste, providers' arrogance, or providers' desire not to be inconvenienced. Nurses' emotions mirrored a sense of failed responsibility for patients. Regret was tempered by nurses' pledges. Critical incidents revealed dilemmas in which nurses' autonomous clinical practice was constrained by feelings of powerlessness.