The Math Immersion intervention was designed to aid the transition-to-proof phase of the undergraduate mathematics major. The Immersion was co-taught by two instructors, one for Intro to Proofs and Abstract Algebra and another for Probability and Statistics and Linear Algebra. This case study documented that efficiency gains directly attributable to course bundling improved the rigor in three of the courses and supported additional instructional time for Abstract Algebra. Immersion students were at least as successful as students in comparable stand-alone courses. For Abstract Algebra, the DFW rate in the Immersion sample (n = 21) was less than half of the university's baseline rate. Immersion student performance on three externally validated assessments indicates the proof-intensive courses resulted in students who performed at a reasonable, objective standard for developing conceptual understanding in Abstract Algebra and for writing and evaluating proofs.