Unlike the situated learning within traditional clinical placements, mixed-reality simulations support a laboratory learning environment where preservice teachers practice their instruction with low risk to the preservice teachers and human students. Simulation experiences can be used in teacher education programs to prepare candidates for the field within a carefully designed curriculum that measures threshold learning. This study explored liminal learning in a teacher education program that used mixed-reality simulations prior to and within clinical placements. A qualitative case study was used to understand the experiences of the participants who were bound by three levels of exposure to simulations. Findings indicated that learning within the mixed-reality simulations could be characterized by three spaces: preprofessional, liminal, and trending toward professional. The integration of mixed-reality simulations within initial teacher preparation core courses facilitated the journey of preservice teachers toward professional identities as they faced instructional and behavioral challenges over the course of three semesters.