The cast is a little surprising -- Jamie Bell is signed to play a Celtic slave, and Channing Tatum is in talks to join him as his Roman owner. I would have expected MacDonald to favor a British cast, and not an all-American type like Tatum, but hey -- he's certainly got the build and bone structure for a Roman officer.
Ninth is based on Rosemary Sutcliff's popular 1954 novel, and centers on a young Roman officer named Marcus Aquila. Forced into an early retirement after being wounded, he travels north with his Celtic slave (who will be played by Bell) to discover what became of his father's Ninth Legion, who vanished in the Scottish Highlands. Marcus also seeks to retake the legion's gold Eagle and reclaim the legion's honor. (The facts Sutcliff based her book on have since been debunked -- the Ninth Legion existed after 117 A.D., and is now believed to have been slaughtered in the eastern half of the Roman Empire. Not as poetic, though.)
As I believe there can never be too many sword-and-sandal epics, I'm anxious to see this one come together, especially since they'll be bowing to authenticity and in the Scottish Highlands. It may be fudgy on the facts, but that doesn't mean it won't be an enjoyable costume drama.