Kate Humble retraces the steps of 15th century explorers as she sets out on a spice trail to India and Sri Lanka. Kate begins her travels on India's `Spice Coast' uncovering the story of pepper, once known as black gold and now the most consumed spice in the world. From India, Kate heads south to Sri Lanka, to the land of cinnamon where she takes part in the delicate process of harvesting the spice.

Kate Humble embarks on a journey around the fabled spice islands of eastern Indonesia in search of two spices that launched epic voyages of discovery, caused bloody wars and shaped empires - nutmeg and cloves. Nutmeg and cloves, grown on an archipelago of tiny volcanic islands, drew European explorers in search of unbelievable wealth, but also led to massacres of local people and the decimation of their culture.

Kate Humble's journey takes her from the Atlas Mountains of Morocco to the plains of Spain as she uncovers the story of the world's most expensive spice, saffron, before crossing the Atlantic to Mexico, in search of vanilla. In the Atlas Mountains, Kate joins local saffron farmer Ahmed and his family to harvest their crop. Kate then journeys to Paplanta in Mexico to meet the Totonac - the original guardian of vanilla.