Regulus, a Roman politician serving under Lepidus, oversees architect Lucius Modestus’s construction of an outdoor bathhouse near volcanic terrain. Tasked with managing the project, he guides Lucius to a warm-water well that accidentally triggers the architect’s time travel to modern Japan, where exposure to innovative bathing culture profoundly influences Lucius’s work. Initially critical of traditional bathhouse aesthetics, Regulus transforms through unresolved grief into a multifaceted figure fixated on merging Roman and Japanese bathing practices. After witnessing Lucius’s cross-cultural discoveries, he channels his anguish into commissioning a Rome-based bathhouse that fuses foreign innovations with local tradition. His obsession stems from a quest for meaning, shifting his trajectory from authoritative skepticism to introspection and gradual openness to progress. Interactions with Lucius reveal Regulus’s evolving perspective, balancing pragmatic loyalty to duty with vulnerability and a hunger for healing. Though his early demeanor prioritizes rigid authority, exposure to Lucius’s ideas fosters adaptability, highlighting tensions between ambition and redemption. His political ties to historical Roman institutions anchor him within the era’s social dynamics, while his arc underscores themes of cultural synthesis and transformation. Personal motives intertwine with professional obligations, framing his journey as one of fractured identity seeking wholeness through reinvention.