City on Fire: A Novel of Pompeii by Tracy Higley and published by Thomas Nelson.
In A.D. 79, Roman patrician Cato settles in the seaside town of Pompeii to build a new business. But corruption and hostility threaten his carefully laid plans. Meanwhile, escaped Jewish slave girl Ariella arrives in town disguised as a gladiator. As the volcano awakens, can they rescue those they love from persecution---and the fiery ash?