Banks, a wealthy landowner turned botanist and natural historian, had influence and connections around the world. He was president of the Royal Society for more than forty years, a driving force behind the establishment of the gardens at Kew and the development of economic botany, an influence in the founding and administration of the New South Wales colony, and a patron of science and exploration. His circle of friends stretched from working class amateur botanists to King George III himself. Enjoying the scope this affords him, O'Brian digresses quite freely, whether to follow some of the explorers and naturalists in whose careers Banks played a role, such as Matthew Flinders, William Bligh, or Robert Brown, or to recount a brief episode in the history of Iceland in which he was peripherally involved.
As in his fiction, O'Brian does a good job of making the differences of a past era seem natural, providing explanation where necessary but without ever being intrusive. Liberal selections from Banks' journals and letters and those of his acquaintances give us a direct connection with him, and at the end one is left feeling almost like an intimate.