The eagle of the ninth
Sutcliff Rosemary
Oxford University Press
The Ninth Legion marched into the mists of northern Britain - and they were never seen again. Four thousand men disappeared and their eagle standard was lost. It's a mystery that's never been solved, until now.
Marcus has to find out what happened to his father, who led the legion. So he sets out into the unknown, on a quest so dangerous that nobody expects him to return.