As part of her department's effort to diversify the history curriculum, Paula Worth began a quest to research and then shape a lesson sequence around the Inkas. Her article shows how she allowed the new topic and its historiography to challenge and extend her own use of sources, particularly oral tradition. Only after wrestling with traces of oral tradition, with scholarship from history and from anthropology, and with the historiography of both Africa and South America, did she start to see a way through for Year 7. The result was a sequence of lessons that could strengthen the coherence of the overall history curriculum in three ways: through encounters with recurring phenomena of world history (such as empire), by teaching richer (more broadly-based and critical) evidential thinking, and by giving pupils more chronological frameworks within and across civilisations.