The first episode sees Kate Humble retraces the steps of fifteenth century explorers as she heads for India and Sri Lanka, the birthplaces of pepper and cinnamon. On India’s spice coast, she tells the story of pepper, the most consumed spice in the world. She does the pepper dance to shake the berries from their stalks and meets farmers fighting a disease that is destroying crops.

In Sri Lanka, the story moves to cinnamon and she learns how the spice is harvested and cinnamon quills are made. She also witnesses the negotiations of local farmers trying to sell the crops they rely on to make their living.

The final episode takes in the Atlas Mountains of Morocco and the plains of Spain for the world’s most expensive spice, saffron, before crossing the Atlantic to Mexico in search of vanilla. In the Atlas Mountains, she joins a local saffron farmer and his family to harvest their crop. In Spain, she joins a blind tasting to sort out the genuine from the fakes and meets the man who tests the DNA of saffron.

In Papantla, the birthplace of vanilla, she meets the Totonac, the original guardians of the spice. She witnesses a fertility dance and comes face to face with the people determined to keep Mexican vanilla alive in the face of competition from other producers