In the decades since Clayton M. Christensen first shared his Theory of Disruptive Innovation with the world, his thinking has led to the creation of billions of dollars of revenue, hundreds of companies, and an entirely new paradigm for how industry entrants upend established giants. Karen Dillon — Christensen’s longtime collaborator and guest editor of this special issue of MIT Sloan Management Review — had a chance to sit down with him before his death in January to learn how he had refined his thinking, what the future of innovation looked like through that lens, and what questions he was still wrestling with. This is an edited version of their conversation.