An Echo in the Darkness, Mark of the Lion Series by Francine Rivers and published by Tyndale.
Book 2 in the Mark of the Lion series, An Echo in the Darkness picks up where A Voice in the Wind leaves off. A year has passed and Hadassah has donned veils to protect her identity as well as the scars that now mark her body. Believed dead, Hadassah finds employment helping a doctor in the poor section of the city and develops a knack for healing through the power of her faith.
When Julia falls ill, Hadassah is forced to confront another difficult decision: should she return to the Valerian household, risking exposure and death, to help her former tormentor in the Christian tradition? The flame between Hadassah and Marcus is ultimately rekindled, though Marcus continues to search for meaning and faith. Turning away from the opulence of Rome, Marcus is led by a whispering voice from the past into a journey that could set him free from the darkness of his soul. Will he find God and spiritual fulfillment, becoming the man Hadassah knows he can be?