The defining qualities of a good enquiry question have been regularly revisited by contributors to Teaching History in the 25 years since Riley first outlined what he saw as three essential characteristics. Despite these endeavours, Ben Arscott notes that the properties of a good enquiry question remain somewhat elusive. His quest to explain why – by examining the different roles that the question plays for the teachers who frame it and the students who are encouraged to answer it – leads him to a striking new metaphor. In this article Arscott explains the metaphor and illustrates its power as a planning tool, with detailed reference to an enquiry question focused on Alfred the Great...