The discovery of and research into penicillin resistance by Sir Edward Abraham and Sir Ernst Chain can be used to teach the concept of natural selection and also multiple nature of science (NOS) objectives associated with Next Generation Science Standards, such as “scientific knowledge is based on empirical evidence” and “science is a human endeavor.” After a brief history of Abraham and Chain's work, we share a detailed multiday lesson plan and rationale for use in an eighth-grade in-person life science classroom. The instructional strategies discussed include analysis of excerpts of Abraham and Chain's published work through a case study jigsaw using an explicit and reflective approach to teaching NOS. The explicit approach used here is the direct instruction of NOS concepts, while the reflective approach allows students to think about and reflect on what they are learning. Instruction includes close reading, direct instruction, small and large group discussions, and writing. Students are asked to create a scavenger hunt map at the end of the multiday lesson and are assessed with an online five-question pre- and post-assessment.