The major characters of the novel are all exiles in some way. The lessons they learn from one another about freedom, self-acceptance, loyalty, and interdependence constitute the novel's themes.

His mother's remarriage and the sale of his family's farm exile Marcus Flavius Aquila from his home in Italy, and then a leg wound forces him out of the army.

His uncle offers him a home in Britain, but he too is an ex-legionary and an expatriate. Marcus's traveling companion, Esca, is a captured British warrior who has been enslaved. Marcus's neighbor Cottia is an orphan who resists her aunt's attempts to turn her into a Romanized Briton, and Guern, who seems to be a Briton, proves to be a former member of the ill-fated Ninth Hispanic.

These characters must come to terms with exile before they can enjoy full lives.

The wolf cub that Esca finds...