Drawing on her wealth of experience and expertise in using visual sources in the classroom, in this article Jane Card explores how a single painting, a portrait of Dido Elizabeth Belle Lindsay and her cousin Lady Elizabeth Murray, might form the basis for a sequence of lessons. Arguing that although highly accessible, images are not straightforward windows into the past, Card demonstrates the vital importance of rich contextual knowledge if teachers are to plan an in-depth enquiry based on a single visual source, and if students are to be able to interrogate in a meaningful way a visual image as a source of evidence. Card describes a number of strategies to help students do this and in so doing shows how a sustained focus on a "little picture" across a sequence of lessons can help students to see a "big story."