Employing narrative inquiry, this study explores how pre-service teachers at a Chinese comprehensive university have been transformed by structured mentoring as a "third space." The research details two narratives under the theoretical framework of the third space. "The Sense of Mission Under the Laugh" highlights the transformation of personal experiences and educational beliefs during mentoring for pre-service teachers' career development. "The Wild Pedagogy" presents how the dichotomy of learning theory and teaching practice is accommodated by hybridity in the third space. Mentoring can become the third space when it includes self-reflecting, hybridizing, and transforming personal and professional experiences and beliefs.