Young's double-slit experiment is one of the most historically significant works in physics, and one that is easily done in an introductory physics class. It is also an excellent example of an investigation that allows us to infer the nature of phenomena beyond direct observation. Unfortunately, perhaps because of this, it is often also an excellent example of the problem with canned cookbook labs. Students dutifully go through the physical motions of the investigation and can easily get good measurements. But actual intellectual engagement is missing. This paper details an instructional sequence that allows an authentic, student-centered approach to this historic investigation. Key to the approach is creating the context in which students can meaningfully devise an investigation into light's wave character.