Daniel Rooke, soldier and astronomer, was always an outsider. As a young lieutenant of marines he arrives in New South Wales on the First Fleet in 1788, and sees his chance. He sets up his observatory away from the main camp, and begins the scientific work that he hopes will make him famous.Aboriginal people soon start to visit his isolated promontory, and a child named Tagaran begins to teach him her language. With meticulous care he records their conversations.An extraordinary friendship forms, and Rooke has almost forgotten he is a soldier when a man is fatally wounded in the infant colony. The lieutenant faces a decision that will define not only who he is but the course of his entire life.

In this profoundly moving novel Kate Grenville returns to the landscape of her much-loved bestseller The Secret River. Inspired by the notebooks of William Dawes, The Lieutenant is a compelling story about friendship and self-discovery by a writer at the peak of her powers.