As in an earlier book, "The Eagle of the Ninth," Rosemary Sutcliff paints here a colorful and convincing picture of Roman Britain ["The Silver Branch"], this time in the latter part of the third century. The story begins during the rule of Carausius, and centers on Justin, newly come to Albion to take up his post of junior surgeon. Uneasily aware of intrigue and unrest about him, Justin and his kinsman Flavius, a young centurion, think at first the turmoil is centered in the conflict between Carausius and his corrupt, self-seeking Finance Minister. But when the Emperor is murdered and the two are forced into hiding, they realize that the whole hope of a civilized and united Britain is at stake. It is only after two years of exile and of adventures with an outcast native tribesman, an ex-gladiator and other members of the loyal underground that Justin...