Invader Books in Order

The novel Invader gathers the threads of the Invader novellas into one longer story and continues the career of Optio Horatius Figulus. It is set in Roman Britain in the aftermath of the first wave of conquest, when the province is far from secure.

Figulus is a career soldier with Celtic roots, which gives him an edge – and a constant source of tension – when dealing with Britain’s tribes. After proving himself in a string of bloody skirmishes, he is given the kind of mission every ambitious optio both wants and fears: take a small, mixed force deep into hostile territory to prop up a wavering client king.

The campaign takes him through forests, marshes and hill forts where Roman armour is more burden than comfort. Bands of warriors melt away before set‑piece battles can be joined, only to strike at night or from the shadows. Behind the spears stand druids, rival chieftains and Roman politicians, all with their own agendas.

As losses mount, Figulus has to decide how far his loyalty to Rome runs when Roman demands clash with the survival of his men and the people he was sent to “protect”. His Celtic ancestry, once an asset, becomes a point of suspicion on both sides.

Invader can be read on its own as a self‑contained tale of a hard campaign at the edge of the empire. For readers who know the novellas, it deepens and completes Figulus’s story, showing how one junior officer’s choices play into the larger arc of Rome’s conquest of Britain.