Zenos, a self-taught healer born in the slums of the Kingdom of Herzeth, has spent years putting up with mistreatment from his adventuring party after being invited to join them. When the party leader banishes him for being useless, claiming his lack of a formal healer's license will damage their reputation among the nobility, Zenos finds himself once again bereft of money and options. Rather than giving up, he decides to put his unlicensed skills to use by opening an underground clinic in a deserted building within the city's shadows.

The building he chooses happens to be inhabited by Carmilla, a wraith who quickly realizes that Zenos possesses a unique advantage healing magic is fatal to the undead, so she reluctantly allows him to use the ground floor for his practice. With the help of Lily, a young elf girl he rescues from slavers by buying and immediately freeing her, Zenos begins treating patients who cannot afford or are forbidden from accessing official healers. Word soon spreads about the brilliant healer working incredible magic in the slums, and even the royal palace begins taking notice.

As Zenos treats members of the warring demi-human gangs that control the slums, he finds himself courted by each of their leaders. Zophia the Tornado, a lizardkin known for robbing rich merchants and assisting the downtrodden, brings her injured followers to his clinic, as do Lynga the catgirl and Loewe the orc. What Zenos does not fully realize is that his healing magic far surpasses the norm, making him a valuable asset that any gang would be unstoppable for possessing. Despite this pressure, he maintains his principles, charging fees on a sliding scale based on what he believes his skills are worth and refusing to play favorites among the factions.

The first season unfolds across two major narrative arcs. The first half establishes Zenos underground clinic and his relationships with the three gang leaders, the wraith Carmilla who provides running commentary from the upper floor, and the young elf Lily who becomes his assistant. The second half shifts focus when Zenos goes undercover at a medical academy for healers, investigating disappearances tied to a mysterious Conductor figure while grappling with questions about who deserves to survive and how healing magic should be used. This arc reveals hints of a larger conspiracy and a shadowy puppet master operating behind the scenes. Throughout both arcs, Zenos remains a stoic but principled protagonist who genuinely wants to help others, driven partly by the memory of the mysterious man who taught him healing arts in his youth. A second season has been announced to continue the story.