I modified the classic Mystery Tube activity to teach not only the nature of science but also the nature of what is not science. In order for evidence and logic to be effective tools for teaching evolution, instructors may first benefit from giving students a tangible reason to set aside any prior nonscientific ideas they bring to the classroom. This activity helps instructors intentionally delineate scientific from nonscientific hypotheses, providing a clear and logical reason for teaching evolutionary theory, but not metaphysical ideas, in the science classroom.