David recreates Agatha Christie's 1922 journey to southern Africa, visiting vineyards, diamond mines, and Victoria Falls. He learns how Agatha's travels inspired her novel The Man in the Brown Suit, and confronts the complex legacy of the British imperialist Cecil Rhodes.

David goes to New Zealand where he explores woollen mills and gold mines and is guided by Maori around geothermal hot springs. He learns how travel fostered Agatha's growing independence, and why his beloved Poirot hates the sea.