Vettius and His Friends — David Drake

For centuries Rome ruled the most diverse grouping of races and cultures ever under a single dominion. But sorcerous powers as black as Time itself gather barbarians to shatter Roman peace. Vettius, a soldier as ruthless as his age demands and Dama, a merchant of wit, wealth and courage meet the dangers of their world. They will each do whatever is necessary for friendship and for the cause they both serve. And a wizards' blood runs as red as any other on the edges of their swords.