The Roman Traitor is a historical novel set in the 1st century BC that features the turbulent political life of the Roman Republic. In the author's opinion, the conspiracy of Catiline was a theme particularly well adapted for the purpose, as being an actual event of vast importance, and in many respects unparalleled in history; as being partially familiar to everyone, thoroughly understood perhaps by no one and particularly interesting because of the dark and mysterious motives of the actors.

"The gate was closed as silently as it had given him entrance; was barred and bolted; and till then no word was interchanged. When all, however, was secure, a deep rich voice, suppressed into a whisper, exclaimed "Sergius?" "Ay!" answered Cataline. "Come on!" and without farther parley they stole into the most secret chambers of the house, fearful as it appeared of the sounds of their own footsteps, much more of their own voices."