The Ghosts of Glevum — Rosemary Rowe

Despite the opulence of the evening's banquet, Libertus is keen to return to his wife and a warm bed. But this feast has a finale to put any diner off his dessert--the guest of honor is found dead in the vomitorium. To Libertus's horror, his patron Marcus Septimus is arrested on suspicion of murder. Then when Libertus is accused of being Marcus's accomplice, he is forced to go on the run. Hiding in a dark corner of the city, he quickly realizes he's an unwelcome visitor to those who haunt the shadows. Soon Libertus is in danger, and this time there's no one to help.