A legionary finds himself thrust into a world of magic and war when his Roman-like empire clashes with a land of sorcery. Marcus, a soldier in the disciplined legions of the Republic of Videssos, is captured during a disastrous campaign against the mysterious kingdom of Valedron. He discovers that Valedron is not merely a rival nation but a land steeped in magic, where sorcerers wield powers beyond his comprehension. Marcus must navigate this alien landscape, survive its dangers, and find a way to return to his own world, all while the fate of his empire hangs in the balance.

The Videssos Cycle, beginning with Swords of the Legion, is recognized for its unique blend of historical military fiction and fantasy elements. Turtledove masterfully contrasts the disciplined, pragmatic approach of the Videssian legions with the potent, often unpredictable magic of Valedron. Readers often praise the intricate world-building and the plausible integration of magic into a Roman-inspired setting. The series is noted for its detailed exploration of military strategy and the ethical dilemmas faced by soldiers in a world where supernatural forces are at play.