The following exploratory study examines the effects of a "Harry Potter"-inspired "border crossing" analogy (HPBCA) on preservice teachers' (n = 25) Teaching English to Speakers of Other Languages (TESOL) content knowledge and disposition toward English language learners (ELLs). The analogy capitalizes on the prior and shared background knowledge many preservice teachers have of J. K. Rowling's "Harry Potter" novels, the related films, and discourses that surround the "Harry Potter" phenomenon. Study results suggest mild agreement among participants of the perceived positive impact of the HPBCA on their TESOL content knowledge, although a slightly less than neutral response toward the perceived impact on their disposition toward ELLs. The results hold implications for the pedagogical use of analogy in teacher education beyond mathematics and science, as well as the role of prior/shared knowledge in teaching and learning.