What to read after Fabiola; Or, The Church of the Catacombs?

The story is set in Rome in the early 4th century AD, during the time of the persecution of Christians under the Roman Emperor Diocletian. The heroine of the book is Fabiola, a young beauty from a noble Roman family. She is spoiled by her father Fabius, who cannot deny her anything. Fabiola seems to have everything, including a superior education in the philosophers, yet under the surface, she is not content with her life. One day, in a fit of rage, she attacks and wounds her slave girl Syra, who is a secret Christian. The proud, spoiled Roman girl is humbled by Syra's humility, maturity, and devotion to her in this situation, and a slow transformation begins, which finally culminates in her conversion to Christianity, brought on by Syra and of her own cousin Agnes, whom she adores and dotes on.